| Word | Definition |
| Abase | to lower; to degrade; to humiliate |
| Abash | to embarrass |
| Abate | subside or moderate |
| Abbreviate | shorten |
| Abdicate | renounce; give up |
| Aberrant | abnormal; atypical |
| Abet | assist, usually in doing something wrong; encourage |
| Abeyance | suspended action |
| Abhor | detest; hate |
| Abject | wretched; lacking pride |
| Abjure | to renounce upon oath |
| Ablution | washing |
| Abnegation | renunciation; self-sacrifice; self-denial |
| Abolish | to cancel; to put an end to |
| Abominable | detestable; extremely unpleasant; very bad |
| Abominate | to loathe; hate |
| Aboriginal | being the first of its kind in a region; primitive; native |
| Abortive | unsuccessful; fruitless |
| Abrasive | rubbing away; tending to grind down |
| Abridge | to condense or to shorten |
| Abrogate | to abolish |
| Abscission | cutting off; separation |
| Abscond | to depart secretly and hide |
| Absolute | complete; totally unlimited; certain |
| Absolve | pardon (an offense) |
| Abstain | refrain; withhold from participation |
| Abstemious | sparing in eating and drinking; temperate: marked by moderation |
| Abstinence | restraint from eating or drinking |
| Abstract | theoretical; not concrete; nonrepresentational |
| Abstruse | obscure; profound; difficult to understand |
| Abusive | coarsely insulting; physically harmful |
| Abut | border upon; adjoin |
| Abysmal | bottomless |
| Abyss | enormous chasm; vast; bottomless pit |
| Academic | related to school; not practical or directly useful |
| Accede | to agree |
| Accelerate | to move faster |
| Accessible | easy to approach; obtainable |
| Accessory | additional object; useful but not essential thing |
| Acclaim | applaud; announce with great approval |
| Acclimate | to adjust to climate or environment |
| Acclivity | an ascending slope |
| Accolade | award of merit |
| Accommodate | to oblige or help someone; adjust or bring into harmony; adapt |
| Accomplice | partner in crime |
| Accord | agreement |
| Accost | approach and speak to someone, often in a challenging or aggressive way |
| Accoutre | to equip or to outfit |
| Accretion | growth; increase |
| Accrue | come about by addition |
| Acerbity | bitterness of speech and temper |
| Acetic | vinegary |
| Acidulous | somewhat acid or harsh in taste or manner; caustic (marked by direct sarcasm) |
| Acknowledge | recognize; admit |
| Acme | peak; pinnacle |
| Acoustics | science of sound; quality that makes a room easy or hard to hear in |
| Acquiesce | to accept or comply passively |
| Acquittal | deliverance from a charge |
| Acrid | sharp, harsh, bitter taste/smell; caustic in language/tone |
| Acrimonious | bitter in words or manner <attack in acrimonious terms> |
| Acrophobia | fear of heights |
| Actuarial | calculating; pertaining to insurance statistics |
| Actuate | motivate |
| Acuity | sharpness |
| Acumen | mental keenness |
| Acute | quickly perceptive; keen; brief and servere |
| Adage | wise saying; proverb |
| Adamant | (N) hard; (ADJ) inflexible |
| Adapt | alter; modify |
| Addendum | addition; appendix to book |
| Addiction | compulsive; habitual need |
| Addle | to confuse (muddle); to become rotten: spoil |
| Address | direct a speech to; deal with or discuss |
| Adept | expert at |
| Adhere | stick fast |
| Adherent | supporter; follower |
| Adjacent | adjoining; neighboring; close by |
| Adjunct | something added on or attached |
| Adjuration | solemn or desperate urging <an adjuration for all citizens of the beleaguered city to take shelter.> |
| Adjutant | staff officer assisting the commander; assistant |
| Admonish | to warn; to express disapproval: reprove |
| Adorn | to decorate |
| Adroit | skillful |
