Nemesis n。 A goddess； divinity of chastisement and vengeance。
neocracy n。 Government administered by new or untried persons。
neo…Darwinsim n。 Darwinism as modified and extended by more recent students。
neo…Latin n。 Modernized Latin。
neopaganism n。 A new or revived paganism。
Neolithic adj。 Pertaining to the later stone age。
neology n。 The coining or using of new words or new meanings of words。
neophyte adj。 Having the character of a beginner。
nestle v。 To adjust cozily in snug quarters。
nestling adj。 Recently hatched。
nettle v。 To excite sensations of uneasiness or displeasure in。
network n。 Anything that presents a system of cross… lines。
neural adj。 Pertaining to the nerves or nervous system。
neurology n。 The science of the nervous system。
neuter adj。 Neither masculine nor feminine。
neutral adj。 Belonging to or under control of neither of two contestants。
nevertheless conj。 Notwithstanding。
Newtonian adj。 Of or pertaining to Sir Isaac Newton； the English philosopher。
niggardly adj。 Stingy。 （no longer acceptable to use）
nihilist n。 An advocate of the doctrine that nothing either exists or can be known。
nil n。 Nothing
nimble adj。 Light and quick in motion or action。
nit n。 The egg of a louse or some other insect。
nocturnal adj。 Of or pertaining to the night。
noiseless adj。 Silent。
noisome adj。 Very offensive； particularly to the sense of smell。
noisy adj。 Clamorous。
nomad adj。 Having no fixed abode。
nomic adj。 Usual or customary。
nominal adj。 Trivial。
nominate v。 To designate as a candidate for any office。
nomination n。 The act or ceremony of naming a man or woman for office。
nominee n。 One who receives a nomination。
non…existent n。 That which does not exist。
non…resident adj。 Not residing within a given jurisdiction。
nonchalance n。 A state of mind indicating lack of interest。
non…batant n。 One attached to the army or navy； but having duties other than that of fighting。
nondescript adj。 Indescribable。
nonentity n。 A person or thing of little or no account。
nonpareil n。 One who or that which is of unequaled excellence。
norm n。 A model。
normalcy n。 The state of being normal。
Norman adj。 Of or peculiar to Normandy； in northern France。
nostrum n。 Any scheme or recipe of a charlatan character。
noticeable adj。 Perceptible。
notorious adj。 Unfavorably known to the general public。
novellette n。 A short novel。
novice n。 A beginner in any business or occupation。
nowadays adv。 In the present time or age。
nowhere adv。 In no place or state。
noxious adj。 Hurtful。
nuance n。 A slight degree of difference in anything perceptible to the sense of the mind。
nucleus n。 A central point or part about which matter is aggregated。
nude adj。 Naked。
nugatory adj。 Having no power or force。
nuisance n。 That which annoys； vexes； or irritates。
numeration n。 The act or art of reading or naming numbers。
numerical adj。 Of or pertaining to number。
nunnery n。 A convent for nuns。
nuptial adj。 Of or pertaining to marriage； especially to the marriage ceremony。
nurture n。 The process of fostering or promoting growth。
nutriment n。 That which nourishes。
nutritive adj。 Having nutritious properties。
oaken adj。 Made of or from oak。
oakum n。 Hemp…fiber obtained by untwisting and picking out loosely the yarns of old hemp rope。
obdurate adj。 Impassive to feelings of humanity or pity。
obelisk n。 A square shaft with pyramidal top； usually monumental or memorative。
obese adj。 Exceedingly fat。
obesity n。 Excessive fatness。
obituary adj。 A published notice of a death。
objective adj。 Grasping and representing facts as they are。
objector n。 One who objects； as to a proposition； measure； or ruling。
obligate v。 To hold to the fulfillment of duty。
obligatory adj。 Binding in law or conscience。
oblique adj。 Slanting； said of lines。
obliterate v。 To cause to disappear。
oblivion n。 The state of having passed out of the memory or of being utterly forgotten。
oblong adj。 Longer than broad： applied most monly to rectangular objects considerably elongated
obnoxious adj。 Detestable。
obsequies n。 Funeral rites。
obsequious adj。 Showing a servile readiness to fall in with the wishes or will of another。
observance n。 A traditional form or customary act。
observant adj。 Quick to notice。
observatory n。 A building designed for systematic astronomical observations。
obsolescence n。 The condition or process of gradually falling into disuse。
obsolescent adj。 Passing out of use； as a word。
obsolete adj。 No longer practiced or accepted。
obstetrician n。 A practitioner of midwifery。
obstetrics n。 The branch of medical science concerned with the treatment and care of women during pregnancy。
obstinacy n。 Stubborn adherence to opinion； arising from conceit or the desire to have one's own way。
obstreperous adj。 Boisterous。
obstruct v。 To fill with impediments so as to prevent passage； either wholly or in part。
obstruction n。 Hindrance。
obtrude v。 To be pushed or to push oneself into undue prominence。
obtrusive adj。 Tending to be pushed or to push oneself into undue prominence。
obvert v。 To turn the front or principal side of （a thing） toward any person or object。
obviate v。 To clear away or provide for； as an objection or difficulty。
occasion n。 An important event or celebration。
Occident n。 The countries lying west of Asia and the Turkish dominions。
occlude v。 To absorb； as a gas by a metal。
occult adj。 Existing but not immediately perceptible。
occupant n。 A tenant in possession of property； as distinguished from the actual owner。
occurrence n。 A happening。
octagon n。 A figure with eight sides and eight angles。
octave n。 A note at this interval above or below any other； considered in relation to that other。
octavo n。 A book； or collection of paper in which the sheets are so folded as to make eight leaves。
octogenarian adj。 A person of between eighty and ninety years。
ocular adj。 Of or pertaining to the eye。
oculist n。 One versed or skilled in treating diseases of the eye。
oddity n。 An eccentricity。
ode n。 The form of lyric poetry anciently intended to be sung。
odious adj。 Hateful。
odium n。 A feeling of extreme repugnance； or of dislike and disgust。
odoriferous adj。 Having or diffusing an odor or scent； especially an agreeable one。
odorous adj。 Having an odor； especially a fragrant one。
off adj。 Farther or more distant。
offhand adv。 Without preparation。
officiate v。 To act as an officer or leader。
officious adj。 Intermeddling with what is not one's concern。
offshoot n。 Something that branches off from the parent stock。
ogre n。 A demon or monster that was supposed to devour human beings。
ointment n。 A fatty preparation with a butter…like consistency in which a medicinal substance exists。
olfactory adj。 of or pertaining to the sense of smell。
olive…branch n。 A branch of the olive…tree； as an emblem of peace。
ominous adj。 Portentous。
omission n。 Exclusion。
omnipotence n。 Unlimited and universal power。
Omnipotent adj。 Possessed of unlimited and universal power。
omniscience n。 Unlimited or infinite knowledge。
omniscient adj。 Characterized by unlimited or infinite knowledge。
omnivorous adj。 Eating or living upon food of all kinds indiscriminately。
onerous adj。 Burdensome or oppressive。
onrush n。 Onset。
onset n。 An assault； especially of troops； upon an enemy or fortification。
onslaught n。 A violent onset。
onus n。 A burden or responsibility。
opalescence n。 The property of bined refraction and reflection of light； resulting in smoky tints。
opaque adj。 Impervious to light。
operate v。 To put in action and supervise the working of。
operative adj。 Active。
operator n。 One who works with or controls some machine or scientific apparatus。
operetta n。 A humorous play in dialogue and music； of more than one act。
opinion n。 A conclusion or judgment held with confidence； but falling short of positive knowledge。
opponent n。 One who supports the opposite side in a debate； discussion； struggle； or sport。
opportune adj。 Especially fit as occurring； said； or done at the right moment。
opportunist n。 One who takes advantage of circumstances to gain his ends。
opportunity n。 Favorable or advantageous chance or opening。
opposite adj。 Radically different or contrary in action or movement。
opprobrium n。 The state of being scornfully reproached or accused of evil。
optic n。 Pertaining to the eye or vision。
optician n。 One who makes or deals in optical instruments or eye…glasses。
optics n。 The science that treats of light and vision； and all that is connected with sight。
optimism n。 The view that everything in nature and the history of mankind is ordered for the best。
option n。 The right； power； or liberty of choosing。
optometry n。 Measurement of the powers of vision。
opulence n。 Affluence。
opulent adj。 Wealthy。
oral adj。 Uttered through the mouth。
orate v。 To deliver an elaborate or formal public speech。
oration n。 An elaborate or formal public speech。
orator n。 One who delivers an elaborate or formal speech。
oratorio n。 A position for solo voices； chorus； and orchestra； generally taken from the Scriptures。
oratory n。 The art of public speaking。
ordeal n。 Anything that severely tests courage； strength； patience； conscience； etc。
ordinal n。 That form of the numeral that shows the order of anything in a series； as first； second； third。
ordination n。 A consecration to the ministry。
ordnance n。 A general name for all kinds of weapons and their appliances used in war。
orgies n。 Wild or wanton revelry。
origin n。 The beginning of that which bees or is made to be。
original adj。 Not copied nor produced by imitation。
originate v。 To cause or constitute the beginning or first stage of the existence of。
ornate adj。 Ornamented to a marked degree。
orthodox adj。 Holding the monly accepted faith。
orthodoxy n。 Acceptance of the mon faith。
orthogonal adj。 Having or determined by right angles。
orthopedic adj。 Relating to the correcting or preventing of deformity
orthopedist n。 One who practices the correcting or preventing of deformity
oscillate v。 To swing back and forth。
osculate v。 To kiss。
ossify v。 to convert into bone。
ostentation n。 A display dictated by vanity and intended to invite applause or flattery。
ostracism n。 Exclusion from intercourse or favor； as in society or politics。
ostracize v。 To e