Crissum
Pronunciation : Cris"sum (krs"sm),
Part of Speech : n.;
Etymology : [NL.; cf. L. crisso to move the haunches.] (Zo?l.)
Definition : Defn: That part of a bird, or the feathers, surrounding the cloacal opening; the under tail coverts.
pl. Crissa (-s.
Source : Webster's Unabridged Dictionary, 1913