having an acid or sharp, biting taste, like vinegar, and the juices of most unripe fruits; acid; tart.-changed, as by keeping, so as to be acid, rancid, or musty, turned.-disagreeable; unpleasant; hence; cross; crabbed; peevish; morose; as, a man of a sour temper; a sour reply.-afflictive; painful.-cold and unproductive; as, sour land; a sour marsh.-a sour or acid substance; whatever produces a painful effect.-to cause to become sour; to cause to turn from sweet to sour; as, exposure to the air sours many substances.-to make cold and unproductive, as soil.-to make unhappy, uneasy, or less agreeable.-to cause or permit to become harsh or unkindly.-to macerate, and render fit for plaster or mortar; as, to sour lime for business purposes.-to become sour; to turn from sweet to sour; as, milk soon sours in hot weather; a kind temper sometimes sours in adversity.