O Set1

oaf	n. stupid, clumsy and awkward person (usu male)
oath	n. (words used in making a) solemn promise to do sth or solemn declaration that sth is true (usu appealing to God, etc as a witness)
oatmeal	n. meal made from crushed oats, used in porridge, oatcakes, etc
obdurate	adj. impossible to change; stubborn
obeisance	n. deep bow (of respect or obedience)
obelisk	n. tall pointed stone pillar with four sides, set up as a monument or landmark
obese	adj. (of people) very fat
obfuscate	v. (deliberately) make (sth) confused or difficult to understand
obituary	n. printed notice (eg in a newspaper) of a person's death, often with a short account of his life and achievements
objective	adj. not influenced by personal feelings or opinions; unbiased; fair
obligatory	adj. required by rule, law or custom; compulsory
oblique	adj. not horizontal or vertical; sloping; slanting
obliterate	v. remove all signs of (sth); rub or blot out
oblivion	n. state of forgetting; state of being unaware or unconscious
oblivious	adj. ~ of/to sth unaware of or not noticing sth; having no memory of sth
obloquy	n. public shame or disgrace; abuse; discredit ;
obnoxious	adj. very unpleasant; nasty; offensive
obscure	adj. not easily or clearly seen or understood; indistinct; hidden
obsequious	adj. ~ (to sb) too willing to obey or serve; too respectful (esp in the hope of getting a reward or favour from sb)
obsequy	exequies; funeral; interment
obsession	n. ~ state of being obsessed
obsessive	adj. of or having an obsession
obsidian	black volcanic rock
obsolete	adj. no longer used; out of date
obstetrician	n. doctor who specializes in obstetrics
obstinate	adj. refusing to change one's opinion or chosen course of action; stubborn
obstreperous	adjnoisy and uncontrolled; unruly
obtrude	v. ~(on/upon sb/sth) (fml ) force (oneself, one's opinions, ideas, etc) upon sb/sth, esp when unwanted
obtrusive	adj. very noticeable or obvious; inclined to obtrude
obtuse	adj. slow to understand; stupid
obviate	v. remove (sth); get rid of
Occident	n. the Occident the countries of the West, ie Europe and America
occlude	to close up or block off:OBSTRUCT
occult	adj. only for those with special knowledge or powers; hidden, secret
oculist	n. specialist in treating diseases and defects of the eye
odds	n. probability or chance
odious	adj. disgusting; hateful
odium	n. general or widespread hatred or disgust felt towards a person or his actions
odoriferous	giving off an order
odorous	adj. having a (pleasant or unpleasant) smell
odyssey	n. long adventurous journey
offensive	adj. upsetting or annoying; insulting
offhand	adj. too casual; abrupt
officious	adj. too ready or willing to give orders, offer advice or help, or use one's authority; bossy and interfering
ogle	v. ~ at sb look or stare at (esp a woman) in a way that suggests sexual interest
olfactory	adj. of or concerned with the sense of smell
oligarchy	n. form of government in which a small group of people hold all the power
ominous	adj. suggesting that sth bad is about to happen; threatening
omnipotent	adj. having unlimited or very great power
omnipresent	adj. present everywhere
omniscient	adj. knowing everything