Ability, capability, capacity, competency, efficacy, power.
Abolish, annul, eradicate, exterminate, obliterate, root out, wipe out.
Abomination, curse, evil, iniquity, nuisance, shame.
Absent, absent-minded, absorbed, abstracted, oblivious, preoccupied.
Absolve, acquit, clear.
Abstemiousness, abstinence, frugality, moderation, sobriety, temperance.
Absurd, ill-advised, ill-considered, ludicrous, monstrous, paradoxical, preposterous, unreasonable, wild.
Abundant, adequate, ample, enough, generous, lavish, plentiful.
Accomplice, ally, colleague, helper, partner.