'Cornu Ammonis' definitions:

Definition of 'Cornu Ammonis'

From: GCIDE

Cornu Ammonis \Cor"nu Am*mo"nis\ ([a^]m*m[=o]"n[i^]s); pl. Cornua Ammonis. [L., horn of Ammon. See Ammonite.] (Paleon.) A fossil shell, curved like a ram's horn; an obsolete name for an ammonite. [1913 Webster]