Webster's Revised Unabridged Dictionary · 1913

Acerous

Acerous ({not transcribed}) , adjective

Same as Acerose.

Acerous , adjective

[Greek α priv. + ke`ras a horn.]

(a)
(Zoology) Destitute of tentacles, as certain mollusks.
(b)
(Zoology) Without antenna, as some insects.