aberration :: wandering or staying away; in optics, failure of rays to focus

abettor :: encourager

abeyance :: suspended action

ablution :: washing

abnegation :: repudiation; self-sacrifice

abstinence :: restraint from eating or drinking

accessory :: additional object: useful but not essential thing

acclivity :: sharp upslope of a hill

accolade :: award of merit

accomplice :: partner in crime

accord :: agreement

accretion :: growth: increase

acerbity :: bitterness of speech and temper

acme :: top: pinnacle

acoustics :: science of sound: quality that makes a room easy or hard to hear in

acquiescence :: submission; compliance

acquittal :: deliverance from a charge

acumen :: mental keenness

adage :: wise saying: proverb

addiction :: compulsive, habitual need

adjunct :: something attached to but holding an inferior position

adjuration :: solemn urging

admonition :: warning

adulation :: flattery: admiration

adumbration :: foreshadowing: outlining

advent :: arrival

adversity :: poverty: misfortune

aegis :: shield; defense

aeon :: long period of time; an age

affidavit :: written statement made under oath

affiliation :: joining: associating with

affinity :: kinship

affirmation :: solemn pledge by one who refuses to take an oath

afflatus :: inspiration

affluence :: abundance: wealth

affray :: public brawl

agenda :: items of business at a meeting

agglomeration :: collection: heap

agility :: nimbleness

agitation :: strong feeling; excitement

agnostic :: one who is skeptical of the existence or knowability of a god

agronomist :: scientist engaged in the management of land

　　alacrity :: cheerful pro