Definition of: sour

(sour) adjective
1. Sharp to the taste; acid; tart, like vinegar: designating one of the four fundamental taste sensations.
2. Having an acid or rancid taste as the result of fermentation; also, pertaining to fermentation.
3. Having a rancid, acid smell or vapor; dank.
4. Misanthropic and crabbed; cross; morose: a sour person, a sour smile.
5. Cold and wet; unpleasant: sour weather.
6. Acid; harsh to crops: said of land.
7. Containing sulfur compounds: said of gasoline.
—v.t & v.i. To become or make sour.
—noun
1. Something sour or distasteful.
2. An acid solution used in bleaching or in curing skins.
3. A treatment with such a solution.
4. A sour or acid beverage: a whisky sour. [œ sūr]
—sour′ly adverb
—sour′ness noun