adj. & n.
adj. 1 not fully formed or done; faulty, incomplete. 2 Gram. (of a tense) denoting a (usu. past) action in progress but not completed at the time in question (e.g. they were singing). 3 Mus. (of a cadence) ending on the dominant chord.
n. the imperfect tense. imperfect rhyme Prosody a rhyme that only partly satisfies the usual criteria (e.g. love and move). imperfectly adv.
[ ME imparfit etc. f. OF imparfait f. L imperfectus (as IN-(1), PERFECT) ]