oaf n.#stupid, awkward person. "Watch what you're doing, you clumsy oaf!" Bill shouted at the waiter who had drenched him with iced coffee.#obdurate adj.# stubborn. He was obdurate in his refusal to listen to our complaints.#obese adj.#fat. It is advisable that obese people try to lose weight.#obfuscate v.#confuse; muddle; cause confusion; make needlessly complex. Was the president's spokesman trying to clarify the hidden weapons mystery, or was he trying to obfuscate the issue so the voters would never figure out what had gone on?#obituary adj.#death notice. I first learned of her death when I read the obituary column in the newspaper. also n.#objective adj.#not influenced by emotions; fair. Even though he was her son, she tried to be objective about his behavior.#objective n.#goal; aim. A degree in medicine was her ultimate objective.#obligatory adj.#binding; required. It is obligatory that books borrowed from the library be returned within two weeks.#oblique adj.#indirect; slanting (deviating from the perpendicular or from a straight line). Casting a quick, oblique glance at the reviewing stand, the sergeant ordered the company to march "Oblique Right."#obliterate v.# destroy completely. The tidal wave obliterated several island villages.#oblivion n.# obscurity; forgetfulness. After a decade of popularity, Hurston's works had fallen into oblivion; no one bothered to read them anymore.#oblivious adj.#inattentive or unmindful; wholly absorbed. Deep in her book, Nancy was oblivious to the noisy squabbles of her brother and his friends.#obnoxious adj.#offensive; objectionable. A sneak and a tattletale, Sid was an obnoxious little brat.#obscure adj.#dark; vague; unclear. Even after I read the poem a fourth time, its meaning was still obscure. obscurity, n.#obscure v.# darken; make unclear. At times he seemed purposely to obscure his meaning, preferring mystery to clarity.#obsequious adj.#slavishly attentive; servile; sycophantic. Helen liked to be served by people who behaved as if they respected themselves; nothing irritated her more than an excessively obsequious waiter or a fawning salesclerk.#obsessive adj.#related to thinking about something constantly; preoccupying. Ballet, which had been a hobby, began to dominate his life: his love of dancing became obsessive. obsession, n.#obsolete adj.#no longer useful; outmoded; antiquated. The invention of the pocket calculator made the slide rule used by generations of engineers obsolete.#obstetrician n.#physician specializing in delivery of babies. Unlike midwives, who care for women giving birth at home, obstetricians generally work in a hospital setting.#obstinate adj.# stubborn; hard to control or treat. We tried to persuade him to give up smoking, but he was obstinate and refused to change. Blackberry stickers are the most obstinate weeds I know: once established in a yard, they're extremely hard to root out. obstinacy, n.#obstreperous adj.#boisterous; noisy. What do you do when an obstreperous horde of drunken policemen goes carousing through your hotel, crashing into potted plants and singing vulgar songs?#obtrude v.#push (oneself or one's ideas) forward or intrude; butt in; stick out or extrude. Because Fanny was reluctant to obtrude her opinions about child-raising upon her daughter-in-law, she kept a close watch on her tongue. obtrusive, adj. #obtuse adj.#blunt; stupid. Because Mr. Collins was too obtuse to take a hint, Elizabeth finally had to tell him that she wouldn't marry him if he were the last man on earth.#obviate v.#prevent; make unnecessary. In the twentieth century, people believed electronic communications would obviate the need for hard copy; they envisioned a paperless society.#odious adj.# hateful; vile. Cinderella's ugly stepsisters had the odious habit of popping their zits in public. #odium n.#strong dislike or contempt; hatefulness; disrepute. Unable to bear the odium attached to their family name, the killer's parents changed their name and moved away from their hometown.#odorous adj.#having an odor. This variety of hybrid tea rose is more odorous than the one you have in your garden.#odyssey n.#long, eventful journey. The refugee's journey from Cambodia was a terrifying odyssey.#offensive adj.#attacking; insulting; distasteful. Getting into street brawls is no minor matter for professional boxers, who are required by law to restrict their offensive impulses to the ring.#offhand adj.#casual; done without prior thought. Expecting to be treated with due propriety by her hosts, Great-Aunt Maud was offended by their offhand manner.#officious adj.#meddlesome; excessively pushy in offering one's services. Judy wanted to look over the new computer models on her own, but the officious salesman kept on butting in with "helpful" advice until she was ready to walk out of the store.#ogle v.#look at amorously; make eyes at. At the coffee house, Walter was too shy to ogle the pretty girls openly; instead, he peeked out at them from behind a rubber plant.#olfactory adj.#concerning the sense of smell. A wine taster must have a discriminating palate and a keen olfactory sense, for a good wine appeals both to the taste buds and to the nose.#oligarchy n.#government by a privileged few. One small clique ran the student council: what had been intended as a democratic governing body had turned into an oligarchy.#ominous adj.# threatening. Those clouds are ominous; they suggest a severe storm is on the way.#omnipotent adj.#all-powerful. Under Stalin, the Soviet government seemed omnipotent: no one dared defy the all-powerful State.#omnipresent adj.#universally present; ubiquitous. The Beatles are a major musical force, whose influence is omnipresent in all contemporary popular music.#omniscient adj.#all-knowing. I may not be omniscient, but I know a bit more than you do, young man!#omnivorous adj.#eating both plant and animal food; devouring everything. Some animals, including man, are omnivorous and eat both meat and vegetables; others are either carnivorous or herbivorous.#onerous adj.#burdensome. He asked for an assistant because his work load was too onerous.#onset n.#beginning; attack. Caught unprepared by the sudden onset of the storm, we rushed around the house closing windows and bringing the garden furniture into shelter. Caught unprepared by the enemy onset, the troops scrambled to take shelter.#onus n.#burden; responsibility. The emperor was spared the onus of signing the surrender papers; instead, he relegated the assignment to his generals.#opalescent adj.#iridescent; lustrous. The oil slick on the water had an opalescent, rainbow-like sheen.#opaque adj.# dark; not transparent. The opaque window shade kept the sunlight out of the room. opacity, n.#opiate n.#medicine to induce sleep or deaden pain; something that relieves emotions or causes inaction. To say that religion is the opiate of the people is to condemn religion as a drug that keeps the people quiet and submissive to those in power.#opportune adj.#timely; well-chosen. Sally looked at her father struggling to balance his checkbook; clearly this would not be an opportune moment to ask him for a raise in her allowance.#opportunist n.# individual who sacrifices principles for expediency by taking advantage of circumstances. Joe is such an opportunist that he tripled the price of bottled water at his store as soon as the earthquake struck. Because it can break water pipes, an earthquake is, to most people, a disaster; to Joe, it was an opportunity.#optician n.#maker and seller of eyeglasses. The patient took the prescription given him by his oculist to the optician.#optimist n.# person who looks on the good side. The pessimist says the glass is half-empty; the optimist says it is half-full.#optimum adj.#most favorable. If you wait for the optimum moment to act, you may never begin your project. also n.#optional adj.#not obligatory; left to one's choice. Most colleges require applicants to submit SAT scores; at some colleges, however, submitting SAT scores is optional.#opulence n.# extreme wealth; luxuriousness; abundance. The glitter and opulence of the ballroom took Cinderella's breath away. opulent, adj. #opus n.#work. Although many critics hailed his Fifth Symphony as his major work, he did not regard it as his major opus.#oracular adj.#prophetic; uttered as if with divine authority; mysterious or ambiguous. Like many others who sought divine guidance from the oracle at Delphi, Oedipus could not understand the enigmatic oracular warning he received.#orator n.# public speaker. The abolitionist Frederick Douglass was a brilliant orator whose speeches brought home to his audience the evils of slavery.#ordain v.#decree or command; grant holy orders; predestine. The king ordained that no foreigner should be allowed to enter the city. The Bishop of Michigan ordained David a deacon in the Episcopal Church. The young lovers felt that fate had ordained their meeting.#ordeal n.#severe trial or affliction. June was so painfully shy that it was an ordeal for her to speak up when the teacher called on her in class.#ordinance n.#decree. Passing a red light is a violation of a city ordinance.#ordination n.#ceremony making someone a minister. At the young priest's ordination, the members of the congregation presented him with a set of vestments. ordain, v.#orgy n.#wild, drunken revelry; unrestrained indulgence in a tendency. The Roman emperor's orgies were far wilder than the toga party in the movie Animal House. When her income tax refund check finally arrived, Sally indulged in an orgy of shopping.#orient v.#get one's bearings; adjust. Philip spent his first day in Denver orienting himself to the city.#orientation n.#act of finding oneself in society. Freshman orientation provides the incoming students with an opportunity to learn about their new environment and their place in it.#ornate adj.# excessively or elaborately decorated. With its elaborately carved, convoluted lines, furniture of the Baroque period was highly ornate.#ornithologist n.#scientific student of birds. Audubon's drawings of American bird life have been of interest not only to ornithologists but also to the general public.#ornithology n.#study of birds. Audubon's studies of American birds greatly influenced the course of ornithology.#orthodox adj.#traditional; conservative in belief. Faced with a problem, he preferred to take an orthodox approach rather than shock anyone. orthodoxy, n.#oscillate v.#vibrate pendulumlike; waver. It is interesting to note how public opinion oscillates between the extremes of optimism and pessimism.#ossify v.#change or harden into bone. When he called his opponent a "bonehead," he implied that his adversary's brain had ossified to the point that he was incapable of clear thinking.#ostensible adj.#apparent; professed; pretended. Although the ostensible purpose of this expedition is to discover new lands, we are really interested in finding new markets for our products.#ostentatious adj.# showy; pretentious; trying to attract attention. Donald Trump's latest casino in Atlantic City is the most ostentatious gambling palace in the East: it easily outglitters its competitors. ostentation, n.#ostracize v.#exclude from public favor; ban. As soon as the newspapers carried the story of his connection with the criminals, his friends began to ostracize him. ostracism, n.#oust v.#expel; drive out. The world wondered if Aquino would be able to oust Marcos from office. ouster, n.#outlandish adj.#bizarre; peculiar; unconventional. The eccentric professor who engages in markedly outlandish behavior is a stock figure in novels with an academic setting.#outmoded adj.#no longer stylish; old-fashioned. Unconcerned about keeping in style, Lenore was perfectly happy to wear outmoded clothes as long as they were clean and unfrayed.#outskirts n.#fringes; outer borders. We lived, not in central London, but in one of those peripheral suburbs that spring up on the outskirts of a great city.#outspoken adj.#candid; blunt. The candidate was too outspoken to be a successful politician; he had not yet learned to weigh his words carefully.#outstrip v.#surpass; outdo. Jesse Owens easily outstripped his white competitors to win the gold medal at the Olympic Games.#outwit v.#outsmart; trick. By disguising himself as an old woman, Holmes was able to outwit his pursuers and escape capture.#ovation n.#enthusiastic applause. When the popular tenor Placido Domingo came on stage in the first act of La Boheme, he was greeted by a tremendous ovation.#overbearing adj.#bossy and arrogant; decisively important. Certain of her own importance, and of the unimportance of everyone else, Lady Bracknell was intolerably overbearing in her manner. "In choosing a husband," she said, "good birth is of overbearing importance; compared to that, neither wealth nor talent signifies."#overt adj.#open to view. According to the United States Constitution, a person must commit an overt act before he may be tried for treason.#overwrought adj.#extremely agitated; hysterical. When Kate heard the news of the sudden tragedy, she became too overwrought to work and had to leave the office early.#