noun

1. A sour substance.

2. Any of several classes of compound having the following properties:

3. Lysergic acid diethylamide (LSD)

adjective

1. Sour, sharp, or biting to the taste; tart; having the taste of vinegar.

   “acid fruits or liquors”

2. Sour-tempered.

3. Of or pertaining to an acid; acidic.

Synonyms: acidic