Acetous \A*ce"tous\ (#; 277), a. [L. acetum vinegar, fr. acere
to be sour.]
1. Having a sour taste; sour; acid. "An acetous spirit."
--Boyle. "A liquid of an acetous kind." --Bp. Lowth.
[1913 Webster]
2. Causing, or connected with, acetification; as, acetous
fermentation.
[1913 Webster]
{Acetous acid}, a name formerly given to vinegar, which is a
dilute solution of acetic acid.
[1913 Webster +PJC]