n. 25B6; adjective
sour wine : ACID, acidic, acidy, acidulated, tart, bitter, sharp, vinegary, pungent; N. Amer. acerb; technical acerbic.
sour milk : BAD, off, turned, curdled, rancid, high, rank, foul, fetid.
a sour old man : EMBITTERED, resentful, rancorous, jaundiced, bitter; nasty, spiteful, irritable, peevish, fractious, cross, crabby, crotchety, cantankerous, disagreeable, petulant, querulous, grumpy, bad-tempered, ill-humoured, sullen, surly, sulky, churlish; informal snappy, grouchy; Brit. informal ratty, stroppy, shirty; N. Amer. informal cranky, soreheaded.
sweet, fresh, amiable.
25B6; verb
the war had soured him : EMBITTER, disillusion, disenchant, poison, alienate; dissatisfy, frustrate.
the dispute soured relations : SPOIL, mar, damage, harm, impair, wreck, upset, poison, blight, tarnish.
improve.