Abate
Lessen
Aberration
Departure from the normal
Abet
Encourage
Abject
Servile; cringing
Abrogate
Cancel
Abstemious
Moderate, especially in the use of food and drink
Abstruse
Profound, obscure
Accolade
Salutation
Accost
Greet; address (negatively)
Accrue
Be added by growth
Acerb
Acid; sour
Acme
Highest point
Acolyte
Novice; young assitance
Acquiesce
Comply; yield
Acrimonious
Biting; sharp
Acumen
Insight
Adamant
Persistent; stuborn
Admonition
Gentle rebuke
Adulation
Excessive praise
Adumbrate
Foreshadow