ichthyology n.#study of fish. Jacques Cousteau's programs about sea life have advanced the cause of ichthyology.#icon n.#religious image; idol. The icons on the walls of the church were painted in the 13th century.#iconoclastic adj.# attacking cherished traditions. Deeply iconoclastic, Jean Genet deliberately set out to shock conventional theatergoers with his radical plays.#ideology n.#system of ideas of a group. For people who had grown up believing in the communist ideology, it was hard to adjust to capitalism.#idiom n.#expression whose meaning as a whole differs from the meanings of its individual words; distinctive style. The phrase "to lose one's marbles" is an idiom: if I say that Joe's lost his marbles, I'm not asking you to find some for him. I'm telling you idiomatically that he's crazy.#idiosyncrasy n.# individual trait, usually odd in nature; eccentricity. One of Richard Nixon's little idiosyncrasies was his liking for ketchup on cottage cheese. One of Hannibal Lecter's little idiosyncrasies was his liking for human flesh. idiosyncratic, adj. #idolatry n.#worship of idols; excessive admiration. Such idolatry of singers of country music is typical of the excessive enthusiasm of youth.#ignite v.#kindle; light. When Desi crooned, "Baby, light my fire," literal-minded Lucy looked around for some paper to ignite.#ignoble adj.#unworthy; base in nature; not noble. Sir Galahad was so pure in heart that he could never stoop to perform an ignoble deed.#ignominy n.# deep disgrace; shame or dishonor. To lose the Ping-Pong match to a trained chimpanzee! How could Rollo stand the ignominy of his defeat? ignominious, adj. #illicit adj.# illegal. The defense attorney maintained that his client had never performed any illicit action.#illimitable adj.#infinite. Man, having explored the far corners of the earth, is now reaching out into illimitable space.#illuminate v.#brighten; clear up or make understandable; enlighten. Just as a lamp can illuminate a dark room, a perceptive comment can illuminate a knotty problem.#illusion n.#misleading vision. It is easy to create an optical illusion in which lines of equal length appear different.#illusory adj.# deceptive; not real. Unfortunately, the costs of running the lemonade stand were so high that Tom's profits proved illusory.#imbalance n.#lack of balance or symmetry; disproportion. To correct racial imbalance in the schools, school boards have bussed black children into white neighborhoods and white children into black ones.#imbibe v.#drink in. The dry soil imbibed the rain quickly.#immaculate adj.#spotless; flawless; absolutely clean. Ken and Jessica were wonderful tenants and left the apartment in immaculate condition when they moved out.#imminent adj.#near at hand; impending. Rosa was such a last-minute worker that she could never start writing a paper till the deadline was imminent.#immobility n.#state of being unable to move. Peter's fear of snakes shocked him into immobility; then the use of his limbs returned to him, and he bolted from the room.#immune adj.#resistant to; free or exempt from. Fortunately, Florence had contracted chicken pox as a child and was immune to it when her baby broke out in spots.#immutable adj.# unchangeable. All things change over time; nothing is immutable.#impair v.# injure; hurt. Drinking alcohol can impair your ability to drive safely; if you're going to drink, don't drive.#impale v.#pierce. He was impaled by the spear hurled by his adversary.#impalpable adj.#imperceptible; intangible. The ash is so fine that it is impalpable to the touch but it can be seen as a fine layer covering the window ledge.#impart v.#reveal or tell; grant. Polly begged Grandma to impart her recipe for rugeleh, but her grandmother wouldn't say a word.#impartial adj.#not biased; fair. Knowing she could not be impartial about her own child, Jo refused to judge any match in which Billy was competing.#impassable adj.#not able to be traveled or crossed. A giant redwood had fallen across the highway, blocking all four lanes: the road was impassable.#impasse n.#predicament from which there is no escape; deadlock. The negotiators reported they had reached an impasse in their talks and had little hope of resolving the deadlock swiftly.#impassive adj.#without feeling; imperturbable; stoical. Refusing to let the enemy see how deeply shaken he was by his capture, the prisoner kept his face impassive.#impeach v.#charge with crime in office; indict. The angry congressman wanted to impeach the president for his misdeeds.#impeccable adj.# faultless. The uncrowned queen of the fashion industry, Diana was acclaimed for her impeccable taste.#impecunious adj.# without money. Though Scrooge claimed he was too impecunious to give alms, he easily could have afforded to be charitable.#impede v.# hinder; block; delay. A series of accidents impeded the launching of the space shuttle.#impediment n.#hindrance; stumbling-block. She had a speech impediment that prevented her speaking clearly.#impel v.#drive or force onward. A strong feeling of urgency impelled her; if she failed to finish the project right then, she knew that she would never get it done.#impenetrable adj.#not able to be pierced or entered; beyond understanding. How could the murderer have gotten into the locked room? To Watson, the mystery, like the room, was impenetrable.#impending adj.#nearing; approaching. The entire country was saddened by the news of his impending death.#impenitent adj.#not repentant. We could see from his tough guy attitude that he was impenitent.#imperative adj.#absolutely necessary; critically important. It is imperative that you be extremely agreeable to Great-Aunt Maud when she comes to tea: otherwise she might not leave you that million dollars in her will. also n.#imperceptible adj.#unnoticeable; undetectable. Fortunately, the stain on the blouse was imperceptible after the blouse had gone through the wash.#imperial adj.#like an emperor; related to an empire. When hotel owner Leona Helmsley appeared in ads as Queen Leona standing guard over the Palace Hotel, her critics mocked her imperial fancies.#imperious adj.#domineering; haughty. Jane rather liked a man to be masterful, but Mr. Rochester seemed so bent on getting his own way that he was actually imperious!#impermeable adj.#impervious; not permitting passage through its substance. Sue chose a raincoat made of Gore-Tex because the material is impermeable to liquids.#impertinent adj.#insolent; rude. His neighbors' impertinent curiosity about his lack of dates angered Ted. It was downright rude of them to ask him such personal questions.#imperturbable adj.#calm; placid; composed. In the midst of the battle, the Duke of Wellington remained imperturbable and in full command of the situation despite the hysteria and panic all around him. imperturbability, n.#impervious adj.#impenetrable; incapable of being damaged or distressed. The carpet salesman told Simone that his most expensive brand of floor covering was warranted to be impervious to ordinary wear and tear. Having read so many negative reviews of his acting, the movie star had learned to ignore them, and was now impervious to criticism.#impetuous adj.#violent; hasty; rash. "Leap before you look" was the motto suggested by one particularly impetuous young man.#impetus n.#incentive; stimulus; moving force. A new federal highway program would create jobs and give added impetus to our economic recovery.#impiety n.#irreverence; lack of respect for God. When members of the youth group draped the church in toilet paper one Halloween, the minister reprimanded them for their impiety.#impinge v.#infringe; touch; collide with. How could they be married without impinging on one another's freedom?#impious adj.#irreverent. The congregation was offended by her impious remarks.#implacable adj.#incapable of being pacified. Madame Defarge was the implacable enemy of the Evremonde family.#implausible adj.# unlikely; unbelievable. Though her alibi seemed implausible, it in fact turned out to be true.#implement v.# put into effect; supply with tools. The mayor was unwilling to implement the plan until she was sure it had the governor's backing. also n.#implicate v.#incriminate; show to be involved. Here's the deal: if you agree to take the witness stand and implicate your partners in crime, the prosecution will recommend that the judge go easy in sentencing you.#implication n.#something hinted at or suggested. When Miss Watson said she hadn't seen her purse since the last time Jim was in the house, the implication was that she suspected Jim had taken it. imply, v.#implicit adj.#understood but not stated. Jack never told Jill he adored her; he believed his love was implicit in his actions.#implore v.#beg. He implored her to give him a second chance.#imply v.#suggest a meaning not expressed; signify. When Aunt Millie said, "My! That's a big piece of pie, young man!" was she implying that Bobby was being a glutton in helping himself to such a huge piece?#imponderable adj.#not able to be determined precisely. Psychology is not a precise science; far too many imponderable factors play a part in determining human behavior.#import n.#importance; meaning. To Miss Manners, proper etiquette was a matter of great import. Because Tom knew so little about medical matters, it took a while for the full import of the doctor's words to sink in.#importunate adj.#urging; demanding. He tried to hide from his importunate creditors until his allowance arrived.#importune v.#beg persistently. Democratic and Republican phone solicitors importuned her for contributions so frequently that she decided to give nothing to either party.#impostor n.#someone who assumes a false identity. "This man is no doctor! He is a fraud!" cried Holmes, exposing the impostor.#impotent adj.#weak; ineffective. Although he wished to break the nicotine habit, he found himself impotent to resist the craving for a cigarette.#impoverished adj.#poor. The loss of their farm left the family impoverished and without hope.#impregnable adj.# invulnerable. Until the development of the airplane as a military weapon, the fort was considered impregnable.#impromptu adj.#without previous preparation; off the cuff; on the spur of the moment. The judges were amazed that she could make such a thorough, well-supported presentation in an impromptu speech.#impropriety n.#improperness; unsuitableness. Because of the impropriety of the punk rocker's slashed T-shirt and jeans, the management refused to admit him to the hotel's very formal dining room.#improvident adj.#thriftless. He was constantly being warned to mend his improvident ways and begin to "save for a rainy day." improvidence, n.#improvise v.#compose on the spur of the moment. She would sit at the piano and improvise for hours on themes from Bach and Handel.#imprudent adj.#lacking caution; injudicious. It is imprudent to exercise vigorously and become overheated when you are unwell.#impudence n.# impertinence; insolence. Kissed on the cheek by a perfect stranger, Lady Catherine exclaimed, "Of all the nerve! Young man, I should have you horse-whipped for your impudence."#impugn v.#dispute or contradict (often in an insulting way); challenge; gainsay. Our treasurer was furious when the finance committee's report impugned the accuracy of his financial records and recommended that he should take bonehead math.#impunity n.#freedom from punishment or harm. A 98-pound weakling can't attack a beachfront bully with impunity: the poor, puny guy is sure to get mashed.#imputation n.#accusation; charge; reproach. Paradoxically, the guiltier he was of the offense with which he was charged, the more he resented the imputation.#inadvertently adv.# unintentionally; by oversight; carelessly. Judy's great fear was that she might inadvertently omit a question on the exam and mismark her whole answer sheet.#inalienable adj.#not to be taken away; nontransferable. The Declaration of Independence asserts that all people possess certain inalienable human rights that no powers on earth can take away.#inane adj.# silly; senseless. There's no point to what you're saying. Why are you bothering to make such inane remarks?#inanimate adj.#lifeless. She was asked to identify the still and inanimate body.#inarticulate adj.#speechless; producing indistinct speech. He became inarticulate with rage and uttered sounds without meaning.#inaugurate v.#start; initiate; install in office. The airline decided to inaugurate its new route to the Far East with a special reduced fare offer. inaugural, adj. #incandescent adj.#strikingly bright; shining with intense heat. If you leave on an incandescent light bulb, it quickly grows too hot to touch.#incantation n.#singing or chanting of magic spells; magical formula. Uttering incantations to make the brew more potent, the witch doctor stirred the liquid in the caldron.#incapacitate v.#disable. During the winter, many people were incapacitated by respiratory ailments.#incarcerate v.#imprison. The civil rights workers were willing to be arrested and even incarcerated if by their imprisonment they could serve the cause.#incarnation n.#act of assuming a human body and human nature. The incarnation of Jesus Christ is a basic tenet of Christian theology.#incendiary n.#arsonist. The fire spread in such an unusual manner that the fire department chiefs were certain that it had been set by an incendiary. also adj. #incense v.#enrage; infuriate. Cruelty to defenseless animals incensed Kit: the very idea brought tears of anger to her eyes. #incentive n.#spur; motive. Mike's strong desire to outshine his big sister was all the incentive he needed to do well in school.#inception n.#start; beginning. She was involved with the project from its inception.#incessant adj.#uninterrupted; unceasing. In a famous TV commercial, the frogs' incessant croaking goes on and on until eventually it turns into a single word: "Bud-weis-er."#inchoate adj.#recently begun; rudimentary; elementary. Before the Creation, the world was an inchoate mass.#incidence n.#rate of occurrence; particular occurrence. Health professionals expressed great concern over the high incidence of infant mortality in major urban areas.#incidental adj.# not essential; minor. The scholarship covered his major expenses at college and some of his incidental expenses as well.#incipient adj.#beginning; in an early stage. I will go to sleep early for I want to break an incipient cold.#incisive adj.# cutting; sharp. His incisive remarks made us see the fallacy in our plans.#incite v.# arouse to action; goad; motivate; induce to exist. In a fiery speech, Mario incited his fellow students to go out on strike to protest the university's anti-affirmative action stand.#inclement adj.#stormy; unkind. In inclement weather, I like to curl up on the sofa with a good book and listen to the storm blowing outside.#incline n.#slope; slant. The architect recommended that the nursing home's ramp be rebuilt because its incline was too steep for wheelchairs.#inclined adj.#tending or leaning toward; bent. Though I am inclined to be skeptical, the witness's manner inclines me to believe his story. also v.#inclusive adj.# tending to include all. The comedian turned down the invitation to join the Players' Club, saying any club that would let him in was too inclusive for him.#incoherence n.#unintelligibility; lack of logic or relevance. "This essay makes no sense at all," commented the teacher, giving it an F because of its incoherence.#incompatible adj.#inharmonious. The married couple argued incessantly and finally decided to separate because they were incompatible. incompatibility, n.#incongruous adj.# not fitting; absurd. Dave saw nothing incongruous about wearing sneakers with his tuxedo; he couldn't understand why his date took one look at him and started to laugh. incongruity, n.#inconsequential adj.# insignificant; unimportant. Brushing off Ali's apologies for having broken the wineglass, Tamara said, "Don't worry about it; it's inconsequential."#inconsistency n.#state of being self-contradictory; lack of uniformity or steadiness. How are lawyers different from agricultural inspectors? While lawyers check inconsistencies in witnesses' statements, agricultural inspectors check inconsistencies in Grade A eggs. inconsistent, adj. #incontinent adj.#lacking self-restraint; licentious. His incontinent behavior off stage so shocked many people that they refused to attend the plays and movies in which he appeared.#incontrovertible adj.# indisputable; not open to question. Unless you find the evidence against my client absolutely incontrovertible, you must declare her not guilty of this charge.#incorporate v.#introduce something into a larger whole; combine; unite. Breaking with precedent, President Truman ordered the military to incorporate blacks into every branch of the armed services. also adj. #incorporeal adj.#lacking a material body; insubstantial. While Casper the friendly ghost is an incorporeal being, nevertheless he and his fellow ghosts make quite an impact on the physical world.#incorrigible adj.# not correctable. Though Widow Douglass hoped to reform Huck, Miss Watson called him incorrigible and said he would come to no good end.#incredulous adj.#withholding belief; skeptical. When Jack claimed he hadn't eaten the jelly doughnut, Jill took an incredulous look at his smeared face and laughed. incredulity, n.#increment n.#increase. The new contract calls for a 10 percent increment in salary for each employee for the next two years.#incriminate v.#accuse. The evidence gathered against the racketeers incriminates some high public officials as well.#incrustation n.#hard coating or crust. In dry dock, we scraped off the incrustation of dirt and barnacles that covered the hull of the ship.#incubate v.#hatch; scheme. Because our supply of electricity has been cut off, we shall have to rely on the hens to incubate these eggs.#inculcate v.#teach; instill. In an effort to inculcate religious devotion, the officials ordered that the school day begin with the singing of a hymn. #incumbent adj.#obligatory; currently holding an office. It is incumbent upon all incumbent elected officials to keep accurate records of expenses incurred in office. also n.#incur v.#bring upon oneself. His parents refused to pay any future debts he might incur.#incursion n.#temporary invasion. The nightly incursions and hit-and-run raids of our neighbors across the border tried the patience of the country to the point where we decided to retaliate in force.#indefatigable adj.# tireless. Although the effort of taking out the garbage tired Wayne out for the entire morning, when it came to partying, he was indefatigable.#indelible adj.#not able to be erased. The indelible ink left a permanent mark on my shirt. Young Bill Clinton's meeting with President Kennedy made an indelible impression on the youth.#indentation n.#notch; deep recess. You can tell one tree from another by examining their leaves and noting the differences in the indentations along the edges of the leaves. indent, v.#indenture v.#bind as servant or apprentice to master. Many immigrants could come to America only after they had indentured themselves for several years. also n.#indeterminate adj.#uncertain; not clearly fixed; indefinite. That interest rates shall rise appears certain; when they will do so, however, remains indeterminate.#indicative adj.#suggestive; implying. A lack of appetite may be indicative of a major mental or physical disorder.#indices n. pl.#signs; indications. Many college admissions officers believe that SAT scores and high school grades are the best indices of a student's potential to succeed in college. n. sg. index.#indict v.# charge. The district attorney didn't want to indict the suspect until she was sure she had a strong enough case to convince a jury. indictment, n.#indifferent adj.# unmoved or unconcerned by; mediocre. Because Ann felt no desire to marry, she was indifferent to Carl's constant proposals. Not only was she indifferent to him personally, but she felt that, given his general silliness, he would make an indifferent husband.#indigenous adj.#native. Cigarettes are made of tobacco, a plant indigenous to the New World.#indigent adj.#poor; destitute. Someone who is truly indigent can't even afford to buy a pack of cigarettes. [Don't mix up indigent and indigenous. See previous sentence.#indignation n.#anger at an injustice. He felt indignation at the ill-treatment of helpless animals.#indignity n.#offensive or insulting treatment. Although he seemed to accept cheerfully the indignities heaped upon him, he was inwardly very angry.#indiscretion n.#lack of tactfulness or sound judgment. Terrified that the least indiscretion could jeopardize his political career, the novice politician never uttered an unguarded word. indiscreet, adj. #indiscriminate adj.# choosing at random; confused. She disapproved of her son's indiscriminate television viewing and decided to restrict him to educational programs.#indisputable adj.#too certain to be disputed. In the face of these indisputable statements, I withdraw my complaint.#indissoluble adj.#permanent. The indissoluble bonds of marriage are all too often being dissolved.#indoctrinate v.#instruct in a doctrine or ideology. Cuban-Americans resisted sending Elian Gonzalez back to Cuba because he would be indoctrinated there with Communist principles.#indolent adj.# lazy. Couch potatoes lead an indolent life lying back on their Lazyboy recliners watching T v. indolence, n.#indomitable adj.#unconquerable; unyielding. Focusing on her game despite all her personal problems, tennis champion Steffi Graf proved she had an indomitable will to win.#indubitable adj.#unable to be doubted; unquestionable. Auditioning for the chorus line, Molly was an indubitable hit: the director fired the leading lady and hired Molly in her place!#induce v.# persuade; bring about. After the quarrel, Tina said nothing could induce her to talk to Tony again. inducement, n.#indulgent adj.#humoring; yielding; lenient. Jay's mom was excessively indulgent: she bought him every Nintendo cartridge and video game on the market. She indulged Jay so much, she spoiled him rotten. #industrious adj.#diligent; hard-working. Look busy when the boss walks by your desk; it never hurts to appear industrious. industry, n.#inebriated adj.#habitually intoxicated; drunk. Abe was inebriated more often than he was sober. Because of his inebriety, he was discharged from his job as a bus driver. #ineffable adj.# unutterable; cannot be expressed in speech. Looking down at her newborn daughter, Ruth felt such ineffable joy that, for the first time in her adult life, she had no words to convey what was in her heart.#ineffectual adj.#not effective; weak. Because the candidate failed to get across his message to the public, his campaign was ineffectual.#inefficacious adj.#not effective; unable to produce a desired result. All Lois's coaxing and urging was inefficacious: Clark still refused to join her and Superman for dinner. inefficacy, n.#inept adj.#lacking skill; unsuited; incompetent. The inept glovemaker was all thumbs.#inequity n.#unfairness. In demanding equal pay for equal work, women protest the basic inequity of a system that gives greater financial rewards to men.#inert adj.# inactive; lacking power to move. "Get up, you lazybones," she cried to her husband, who lay in bed inert. inertia, n.#inevitable adj.#unavoidable. Though death and taxes are both supposedly inevitable, some people avoid paying taxes for years.#inexorable adj.# relentless; unyielding; implacable. After listening to the pleas for clemency, the judge was inexorable and gave the convicted man the maximum punishment allowed by law.#infallible adj.#unerring. Jane refused to believe the pope was infallible, reasoning, "All human beings are capable of error. The pope is a human being. Therefore, the pope is capable of error."#infamous adj.#notoriously bad. Charles Manson and Jeffrey Dahmer are both infamous killers.#infantile adj.#childish. When will he outgrow such infantile behavior?#infer v.#deduce; conclude. From the students' glazed looks, it was easy for me to infer that they were bored out of their minds. inference, n.#infernal adj.#pertaining to hell; devilish. Batman was baffled: he could think of no way to hinder the Joker's infernal scheme to destroy the city.#infidel n.#unbeliever. The Saracens made war against the infidels.#infiltrate v.#pass into or through; penetrate (an organization) sneakily. In order to be able to infiltrate enemy lines at night without being seen, the scouts darkened their faces and wore black coveralls. infiltrator, n.#infinitesimal adj.#exceedingly small; so small as to be almost nonexistent. Making sure everyone was aware she was on an extremely strict diet, Melanie said she would have only an infinitesimal sliver of pie.#infirmity n.#weakness. Her greatest infirmity was lack of willpower.#inflated adj.#exaggerated; pompous; enlarged (with air or gas). His claims about the new product were inflated; it did not work as well as he had promised.#influx n.#flowing into. The influx of refugees into the country has taxed the relief agencies severely.#informal adj.#absence of ceremony; casual. The English teacher preferred informal discussions to prepared lectures.#infraction n.#violation (of a rule or regulation); breach. When Dennis Rodman butted heads with that referee, he committed a clear infraction of NBA rules.#infuriate v.#enrage; anger. Her big brother's teasing always infuriated Margaret; no matter how hard she tried to keep her temper, he always got her goat.#infusion n.#act of introducing or instilling a quality; liquid solution. The rookie quarterback brought an infusion of new life and vigor to the tired team. infuse, v.#ingenious adj.# clever; resourceful. Kit admired the ingenious way that her computer keyboard opened up to reveal the built-in CD-ROM below. ingenuity, n.#ingenue n.#an artless girl; an actress who plays such parts. Although she was forty, she still insisted that she be cast as an ingenue and refused to play more mature roles.#ingenuous adj.#naive and trusting; young; unsophisticated. The woodsman had not realized how ingenuous Little Red Riding Hood was until he heard that she had gone off for a walk in the woods with the Big Bad Wolf.#ingrained adj.#deeply established; firmly rooted. Try as they would, the missionaries were unable to uproot the ingrained superstitions of the natives.#ingrate n.#ungrateful person. That ingrate Bob sneered at the tie I gave him.#ingratiate v.#make an effort to become popular with. In All About Eve, the heroine, an aspiring actress, wages a clever campaign to ingratiate herself with Margo Channing, an established star.#inherent adj.# firmly established by nature or habit. Katya's inherent love of justice caused her to champion anyone she considered treated unfairly by society.#inhibit v.#restrain; retard or prevent. Only two things inhibited him from taking a punch at Mike Tyson: Tyson's left hook, and Tyson's right jab. The protective undercoating on my car inhibits the formation of rust.#inimical adj.#unfriendly; hostile; harmful; detrimental. I've always been friendly to Martha. Why is she so inimical to me?#inimitable adj.#matchless; not able to be imitated. We admire Auden for his inimitable use of language; he is one of a kind.#iniquitous adj.#wicked; immoral; unrighteous. Whether or not King Richard III was responsible for the murder of the two young princes in the Tower, it was an iniquitous deed. iniquity, n.#initiate v.#begin; originate; receive into a group. The college is about to initiate a program in reducing math anxiety among students.#injurious adj.#harmful. Smoking cigarettes can be injurious to your health.#inkling n.#hint. This came as a complete surprise to me as I did not have the slightest inkling of your plans.#innate adj.# inborn. Mozart's parents soon recognized young Wolfgang's innate talent for music.#innocuous adj.# harmless. An occasional glass of wine with dinner is relatively innocuous and should have no ill effect on you.#innovation n.# change; introduction of something new. Although Richard liked to keep up with all the latest technological innovations, he didn't always abandon tried and true techniques in favor of something new. innovate, v.#innovative adj.#novel; introducing a change. The establishment of our SAT computer data base has enabled us to come up with some innovative tactics for doing well on the SAT.#innuendo n.#hint; insinuation. I can defend myself against direct accusations; innuendos and oblique attacks on my character are what trouble me.#inopportune adj.#untimely; poorly chosen. A rock concert is an inopportune setting for a quiet conversation.#inordinate adj.#unrestrained; excessive. She had an inordinate fondness for candy, eating two or three boxes in a single day.#inquisitor n.#questioner (especially harsh); investigator. Fearing being grilled ruthlessly by the secret police, Masha faced her inquisitors with trepidation.#insalubrious adj.#unwholesome; not healthful. The mosquito-ridden swamp was an insalubrious place, a breeding ground for malarial contagion.#insatiable adj.#not easily satisfied; unquenchable; greedy. David's appetite for oysters was insatiable: he could easily eat four dozen at a single sitting.#inscrutable adj.#impenetrable; not readily understood; mysterious. Experienced poker players try to keep their expressions inscrutable, hiding their reactions to the cards behind a so-called "poker face."#insensible adj.#unconscious; unresponsive. Sherry and I are very different; at times when I would be covered with embarrassment, she seems insensible to shame.#insidious adj.#treacherous; stealthy; sly. The fifth column is insidious because it works secretly within our territory for our defeat.#insightful adj.#discerning; perceptive. Sol thought he was very insightful about human behavior, but he was actually clueless as to why people acted the way they did.#insinuate v.#hint; imply; creep in. When you said I looked robust, did you mean to insinuate that I'm getting fat?#insipid adj.# lacking in flavor; dull. Flat prose and flat ginger ale are equally insipid: both lack sparkle.#insolence n.#impudent disrespect; haughtiness. How dare you treat me so rudely! The manager will hear of your insolence. insolent, adj. #insolvent adj.# bankrupt; unable to repay one's debts. Although young Lord Widgeon was insolvent, he had no fear of being thrown into debtors' prison, for he was sure that if his creditors pressed him for payment his wealthy parents would repay what he owed. insolvency, n.#insomnia n.#wakefulness; inability to sleep. He refused to join us in a midnight cup of coffee because he claimed it gave him insomnia.#instigate v.# urge; start; provoke. Rumors of police corruption led the mayor to instigate an investigation into the department's activities.#insubordination n.#disobedience; rebelliousness. At the slightest hint of insubordination from the sailors of the Bounty, Captain Bligh had them flogged; finally, they mutinied.#insubstantial adj.#lacking substance; insignificant; frail. His hopes for a career in acting proved insubstantial; no one would cast him, even in an insubstantial role.#insularity n.# narrow-mindedness; isolation. The insularity of the islanders manifested itself in their suspicion of anything foreign. insular, adj. #insulated adj.#set apart; isolated. A well-to-do bachelor, James spent his money freely, insulated from the cares of his friends, who had families to support.#insuperable adj.# insurmountable; unbeatable. Though the odds against their survival seemed insuperable, the Apollo 13 astronauts reached earth safely.#insurgent adj.#rebellious. Because the insurgent forces had occupied the capital and had gained control of the railway lines, several of the war correspondents covering the uprising predicted a rebel victory.#insurmountable adj.#overwhelming; unbeatable; insuperable. Faced by almost insurmountable obstacles, the members of the underground maintained their courage and will to resist.#insurrection n.#rebellion; uprising. In retrospect, given how badly the British treated the American colonists, the eventual insurrection seems inevitable.#intangible adj.#not able to be perceived by touch; vague. Though the financial benefits of his Oxford post were meager, Lewis was drawn to it by its intangible rewards: prestige, intellectual freedom, the fellowship of his peers.#integral adj.#complete; necessary for completeness. Physical education is an integral part of our curriculum; a sound mind and a sound body are complementary.#integrate v.#make whole; combine; make into one unit. We hope to integrate the French, Spanish, and Italian programs into a combined Romance languages department.#integrity n.# uprightness; wholeness. Lincoln, whose personal integrity has inspired millions, fought a civil war to maintain the integrity of the Republic, that these United States might remain undivided for all time.#intellect n.#higher mental powers. If you wish to develop your intellect, read the great books.#intelligentsia n.#the intelligent and educated classes [often used derogatorily#intemperate adj.#immoderate; excessive; extreme. In a temper, Tony refused to tone down his intemperate remarks.#inter v.#bury. They are going to inter the body tomorrow at Broadlawn Cemetery.#interim n.#meantime. The company will not consider our proposal until next week; in the interim, let us proceed as we have in the past.#interloper n.#intruder; unwanted meddler. The merchant thought of his competitors as interlopers who were stealing away his trade.#interment n.#burial. Interment will take place in the church cemetery at 2 p.m. Wednesday.#interminable adj.#endless. Although his speech lasted for only twenty minutes, it seemed interminable to his bored audience.#intermittent adj.#periodic; on and off. The outdoor wedding reception had to be moved indoors to avoid the intermittent showers that fell on and off all afternoon.#interrogate v.#question closely; cross-examine. Knowing that the Nazis would interrogate him about his background, the secret agent invented a cover story that would help him meet their questions.#intervene v.# come between. When two close friends get into a fight, be careful if you try to intervene; they may join forces to gang up on you.#intimacy n.#closeness, often affectionate; privacy; familiarity. In a moment of rare intimacy, the mayor allowed the reporters a glimpse of his personal feelings about his family. intimate, adj. #intimate v.#hint; suggest. Was Dick intimating that Jane had bad breath when he asked if she'd like a breath mint?#intimidate v.# frighten. I'll learn karate and then those big bullies won't be able to intimidate me any more.#intractable adj.# unruly; stubborn; unyielding. Charlie Brown's friend Pigpen was intractable: he absolutely refused to take a bath.#intransigence n.#refusal of any compromise; stubbornness. The negotiating team had not expected such intransigence from the striking workers, who rejected any hint of a compromise. intransigent, adj. #intrepid adj.# fearless. For her intrepid conduct nursing the wounded during the war, Florence Nightingale was honored by Queen Victoria.#intricate adj.#complex; knotty; tangled. Philip spent many hours designing mazes so intricate that none of his classmates could solve them. intricacy, n.#intrinsic adj.#essential; inherent; built-in. Although my grandmother's china has little intrinsic value, I shall always cherish it for the memories it evokes.#introspective adj.#looking within oneself. Though young Francis of Assisi led a wild and worldly life, even then he had introspective moments during which he examined his soul.#introvert n.#one who is introspective; inclined to think more about oneself. Uncommunicative by nature and disinclined to look outside himself, he was a classic introvert.#intrude v.#trespass; enter as an uninvited person. She hesitated to intrude on their conversation.#intuition n.#immediate insight; power of knowing without reasoning. Even though Tony denied that anything was wrong, Tina trusted her intuition that something was bothering him. intuitive, adj. #inundate v.# overwhelm; flood; submerge. This semester I am inundated with work: You should see the piles of paperwork flooding my desk. Until the great dam was built, the waters of the Nile used to inundate the river valley like clockwork every year.#inured adj.#accustomed; hardened. She became inured to the Alaskan cold.#invalidate v.#weaken; destroy. The relatives who received little or nothing sought to invalidate the will by claiming that the deceased had not been in his right mind when he had signed the document.#invasive adj.#tending to spread aggressively; intrusive. Giving up our war with the invasive blackberry vines that had taken over the back yard, we covered the lawn with concrete. invade, v.#invective n.#abuse. He had expected criticism but not the invective that greeted his proposal. inveigh, v.#inveigle v.#entice; persuade; wheedle. Flattering Adam about his good taste in food, Eve inveigled him into taking a bite of her apple pie.#inverse adj.#opposite. There is an inverse ratio between the strength of light and its distance.#invert v.# turn upside down or inside out. When he inverted his body in a handstand, he felt the blood rush to his head.#inveterate adj.#deep-rooted; habitual. An inveterate smoker, Bob cannot seem to break the habit, no matter how hard he tries.#invidious adj.#designed to create ill will or envy. We disregarded her invidious remarks because we realized how jealous she was.#invigorate v.#energize; stimulate. A quick dip in the pool invigorated Meg, and with renewed energy she got back to work.#invincible adj.#unconquerable. Superman is invincible.#inviolable adj.#secure from corruption, attack, or violation; unassailable. Batman considered his oath to keep the people of Gotham City safe inviolable: nothing on earth could make him break this promise.#invocation n.#prayer for help; calling upon as a reference or support. The service of Morning Prayer opens with an invocation during which we ask God to hear our prayers.#invoke v.#call upon; ask for. She invoked her advisor's aid in filling out her financial aid forms.#invulnerable adj.#incapable of injury. Achilles was invulnerable except in his heel.#iota n.#very small quantity. She hadn't an iota of common sense.#irascible adj.#irritable; easily angered. Miss Minchin's irascible temper intimidated the younger schoolgirls, who feared she'd burst into a rage at any moment.#irate adj.#angry. When John's mother found out he had overdrawn his checking account for the third month in a row, she was so irate she could scarcely speak to him.#ire n.#anger. The waiter tried unsuccessfully to placate the ire of the diner who had found a cockroach in her soup.#iridescent adj.#exhibiting rainbowlike colors. She admired the iridescent hues of the oil that floated on the surface of the water.#irksome adj.#annoying; tedious. He found working on the assembly line irksome because of the monotony of the operation he had to perform. irk, v.#ironic adj.# resulting in an unexpected and contrary outcome. It is ironic that his success came when he least wanted it.#irony n.#hidden sarcasm or satire; use of words that seem to mean the opposite of what they actually mean. Gradually his listeners began to realize that the excessive praise he was lavishing on his opponent was actually irony; he was in fact ridiculing the poor fool. #irrational adj.#illogical; lacking reason; insane. Many people have such an irrational fear of snakes that they panic at the sight of a harmless garter snake.#irreconcilable adj.#incompatible; not able to be resolved. Because the separated couple were irreconcilable, the marriage counselor recommended a divorce.#irrefutable adj.#indisputable; incontrovertible; undeniable. No matter how hard I tried to find a good comeback for her argument, I couldn't think of one: her logic was irrefutable.#irrelevant adj.#not applicable; unrelated. No matter how irrelevant the patient's mumblings may seem, they give us some indications of what he has on his mind.#irremediable adj.#incurable; uncorrectable. The error she made was irremediable; she could see no way to repair it.#irreparable adj.#not able to be corrected or repaired. Your apology cannot atone for the irreparable damage you have done to her reputation.#irrepressible adj.#unable to be restrained or held back. My friend Kitty's curiosity was irrepressible: she poked her nose into everybody's business and just laughed when I warned her that curiosity killed the cat. #irreproachable adj.# blameless; impeccable. Homer's conduct at the office party was irreproachable; even Marge didn't have anything bad to say about how he behaved.#irresolute adj.#uncertain how to act; weak. Once you have made your decision, don't waver; a leader should never appear irresolute.#irretrievable adj.#impossible to recover or regain; irreparable. The left fielder tried to retrieve the ball, but it flew over the fence, bounced off a wall, and fell into the sewer: it was irretrievable.#irreverence n.#lack of proper respect. Some audience members were amused by the irreverence of the comedian's jokes about the Pope; others felt offended by his lack of respect for their faith. irreverent, adj. #irrevocable adj.#unalterable; irreversible. As Sue dropped the "Dear John" letter into the mailbox, she suddenly had second thoughts and wanted to take it back, but she could not: her action was irrevocable.#itinerant adj.#wandering; traveling. He was an itinerant peddler and traveled through Pennsylvania and Virginia selling his wares. also n.#itinerary n.#plan of a trip. Disliking sudden changes in plans when she traveled abroad, Ethel refused to make any alterations in her itinerary.#