2. Changed, as by keeping, so as to be acid, rancid, or musty, turned.

3. Disagreeable; unpleasant; hence; cross; crabbed; peevish; morose;

as, a man of a sour temper; a sour reply. "A sour countenance." Swift.

He was a scholar . . . Lofty and sour to them that loved him not,

But to those men that sought him sweet as summer.

Shak.