adjective
plenty
Synonyms: abundant, acceptable, adequate, all right already, ample, bellyful, bounteous, bountiful, comfortable, competent, complete, copious, decent, enough already, fed up, full, had it, last straw, lavish, plenteous, plentiful, replete, satisfactory, satisfying, sick and tired of, sufficient, sufficing, suitable, unlimited, up to here
Antonyms: inadequate, insufficient
adverb
adequately
Synonyms: abundantly, acceptably, admissibly, amply, averagely, barely, commensurately, decently, fairly, moderately, passably, proportionately, rather, reasonably, satisfactorily, so-so, sufficiently, tolerably
Antonyms: inadequately
noun
plenty
Synonyms: abundance, adequacy, ampleness, ample supply, competence, plenitude, right amount, sufficiency, sufficient
Antonyms: inadequacy, insufficiency