Available Definitions:
1) superl. - Having an acid or sharp, biting taste, like vinegar, and the juices of most unripe fruits; acid; tart.
2) superl. - Changed, as by keeping, so as to be acid, rancid, or musty, turned.
3) superl. - Disagreeable; unpleasant; hence; cross; crabbed; peevish; morose; as, a man of a sour temper; a sour reply.
4) superl. - Afflictive; painful.
5) superl. - Cold and unproductive; as, sour land; a sour marsh.
6) n. - A sour or acid substance; whatever produces a painful effect.
7) v. t. - To cause to become sour; to cause to turn from sweet to sour; as, exposure to the air sours many substances.
8) v. t. - To make cold and unproductive, as soil.
9) v. t. - To make unhappy, uneasy, or less agreeable.
10) v. t. - To cause or permit to become harsh or unkindly.
11) v. t. - To macerate, and render fit for plaster or mortar; as, to sour lime for business purposes.
12) v. i. - To become sour; to turn from sweet to sour; as, milk soon sours in hot weather; a kind temper sometimes sours in adversity.