- abstinent: abstaining, voluntarily not doing something, especially something pleasant that is bad for you
- abstract: theoretical, impersonal
- abstruse: hard to understand
- abysmal: extremely hopeless, bottomless
- accolade: an award, an honor
- accost: to approach and speak to aggressively
- acerbic: bitter, sour, severe
- acquiesce: to comply passively
- acrid: harsh, like acid
- acrimonious: full of spite, bitter, nasty
- acumen: keenness of judgment, mental sharpness