| Term | Definition |
| astral | adj. relating to the stars |
| astringent | adj. binding; causing contraction |
| astronomical | adj. enormously large or extensive |
| astute | adj. wise; shrewd; keen |
| asunder | adj. into parts; apart |
| asylum | n. place of refuge or shelter; protection |
| asymmetric | adj. not identical on both sides of a dividing central line |
| atavism | n. resemblacne to remote ancestors rather than to parents; deformity returning after passage of two or more generation |
| atheistic | adj. denying the existence of God |
| atlas | n. a bound volumle of maps, charts, or tables |
| atone | v. make amends for; pay for |
| atrocity | n. brutal deed |
| atrophy | n. wasting away |
| attain | v. achieve or accomplish; gain |
| attentive | adj. alert and watchful; considerate; thoughtful |
| attenuate | v. make thin; weaken |
| attest | v. testify, bear witness |
| attribute | n. essential quality |
| attribute | v. ascribe; explain |
| attrition | n. gradual decrease in numbers; reduction in the work force without firing employees |
| atypical | adj. not normal |
| audacious | adj. daring; bold |
| audit | n. examination of accounts |
| auditory | adj. pertaining to the sense of hearing |
| augment | v. increase; add to |
| augury | n. omen; prophecy |
| august | adj. impressive; majestic |
| aureole | n. sun's corona; halo |
| auroral | adj. pertaining to the aurora borealis |
| auspicious | adj. favoring success |
| austere | adj. forbiddingly stern; severely simple and unornamented |
| authenticate | v. prove genuine |
| authoritarian | adj. subordinating the individual to the state; completely dominating another's will |
| authoritative | adj. having the weight of authority; peremptory and dictatorial |
| autocratic | adj. having absolute, unchecked power; dictorial |
| automation | n. meachanism that imitates actions of humans |
| autonomous | adj. self governing |
| autopsy | n. examination of a dead body; post-mortem |
| auxiliary | adj. helper, additional or subsidiary |
| avalanche | n. great mass of alling snow and ice |
| avarice | n. greediness for wealth |
| avenge | b. take vengeance for something ( or on behalf of someone ) |
| averse | adj. reluctant; disinclined |
| aversion | n. firm dislike |
| avert | v. prevent; turn away |
| aviary | n. enclosure for birds |
| avid | adj. greedy; eager for |
| avocation | n. secondary or minor occupation |
| avow | v. declare openly |
| avuncular | adj. like an uncle |
| awe | n. solemn wonder |
| awry | adv. distorted; crooked |
| axiom | n. self-evident truth requring no proof |
| azure | adj. sky blue |
| babble | v. chatter idly |
| bacchanalian | adj. drunken |
| badger | v. pester; annoy |
| badinage | n. teasing conversation |
| baffle | v. frustrate; perplex |
| bait | v. harass; tease |
| baleful | adj. deadly; having a malign influence; ominous |
| balk | v. foil or thwart; stop short; refuse to go one |
| ballast | n. heavy substance used to add stability or weight |
| balm | n. something that relieves pain |
| balmy | adj. mild; fragrant |
| banal | adj. hackneyed; commonplace; trite; lacking originality |
| bandy | v. discuss lightly or glibly; exchange ( words ) heatedly |
| bane | n. cause of ruin; curse |
| bantering | adj. good-natured ridiculing |
| barb | b. sharp projection from fishhook, etc.; openly cutting remark |