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