Synonyms and related words :
acerb, acerbate, acerbic, acescent, bearish, bilious, bitter, cankered, choleric, crab, crabbed, cranky, cross-grained, crotchety, dry, dyspeptic, embittered, green, jaundiced, ornery, pickled, pungent, sec, sour, sour as vinegar, sour-tempered, soured, sourish, tart, tartish, unripe, unsweet, unsweetened, vinegary, waspish