Webster's Revised Unabridged Dictionary · 1913

Acetous

Acetous (#; 277) , adjective

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

1.
Having a sour taste; sour; acid.
An acetous spirit. — Boyle
A liquid of an acetous kind. — Bp. Lowth
2.
Causing, or connected with, acetification; as, acetous fermentation.
Collocations (1)
Acetous acid , a name formerly given to vinegar, which is a dilute solution of acetic acid.