Webster's Revised Unabridged Dictionary · 1913

Acetic

Acetic (#; 277) , adjective

[Latin acetum vinegar, from acere to be sour.]

(a)
(Chemistry) Of a pertaining to vinegar; producing vinegar; producing vinegar; as, acetic fermentation.
(b)
(Chemistry) Pertaining to, containing, or derived from, acetyl, as acetic ether, acetic acid. The latter is the acid to which the sour taste of vinegar is due.