acid
adjective
°Sour, sharp, or biting to the taste; tart; having the taste of vinegar.
"acid fruits or liquors"
°Sour-tempered.
noun
°A sour substance.
°Any of a class of water-soluble compounds, having sour taste, that turn blue litmus red, and react with some metals to liberate hydrogen, and with bases to form salts.
synonyms: acidic