| Term | Definition |
| appropriate | to take without permission |
| appurtenance | an accessory |
| apropos | appropriate |
| apt | appropriate |
| aptitude | capacity for learning |
| arbiter | a judge |
| arbitrary | random |
| arcade | game room |
| arcane | mysterious |
| archaic | very old |
| archetype | an original model or pattern |
| archipelago | a group of islands |
| archives | a place where historical documents are stored |
| ardent | passionate |
| arduous | hard |
| arid | dry |
| arisocratic | of noble birth |
| armament | implement of war |
| armistice | truce |
| arraign | to accuse |
| arrant | very bad |
| arrears | unpaid debts |
| arsenal | a supply |
| artful | wily |
| artifice | cunning |
| artisan | a person skilled in a craft |
| ascertain | to find out definitely |
| ascendancy | supremacy |
| ascetic | hermitlike |
| ascribe | to credit |
| askance | with suspicion |
| aspersion | damning remark |
| assail | to attack |
| assert | to affirm |
| assess | to evaluate |
| assiduous | hardworking |
| assimilate | to absorb |
| assuage | to soothe |
| astringent | harsh |
| astute | shrewd |
| asylum | a mental hospital |
| atone | to make amends |
| atrophy | to wither away |
| attest | to give proof |
| attribute | to credit |
| attrition | gradual loss |
| audacity | boldness |
| augment | to make bigger |
| augur | to predict |
| august | inspiring admiration |
| auspiced | protection |
| auspicious | favorable |
| austere | stern |
| autocratic | bossy |
| autonomous | acting independently |
| auxiliary | secondary |
| avail | to help |
| avarice | greed |
| aversion | dislike |
| avert | to prevent |
| avid | eager |
| avow | to claim |
| avuncular | like an uncle |
| awry | off course |
| axiom | a widely accepted saying |
| babble | to utter meaningless sounds |
| banal | ordinary |
| bacchanal | a party animal |
| baleful | menacing |
| balk | to stop short |
| ballyhoo | uproar |
| balm | soothe |
| bandy | to exchange |
| bane | cause of harm |
| banter | an exchange of remarks |
| bastion | stronghold |
| baroque | flamboyant |
| barrage | artillery fire |
| bauble | trinket |
| bedlam | uproar |
| beget | to cause |
| begrudge | to be reluctant to give |
| behest | command |
| belabor | to go over |
| beleaguer | to harass |
| belie | to contradict |
| belittle | to put someone down |
| belligerent | combative |
| bemoan | to mourn about |
| bemused | confused |
| benediction | a blessing |
| benefactor | one who provides help |
| benevolent | kind |
| benighted | ignorant |
| benign | kind |
| bequest | something left in a will |
| bereaved | deprived |
| beset | harass |
| bestow | to confer |
| bilious | cranky |