1. stinging Acid, sour, and bitter agree in being contrasted with sweet, but the two former are sharply distinguished from the latter. Acid or sour is the taste of vinegar or lemon-juice; bitter th Synonyms: bitter, acerb, acidulous, caustic, pungent, stinging, acetous, acrid, cutting, savage, tart, acid, acrimonious, harsh, sharp, vinegarish, acidulated, biting, irate, sour, virulent Antonyms: dulcet, honeyed, luscious, nectared, saccharine, sweet