'Crissa' definitions:

Definition of 'Crissa'

From: GCIDE

Crissum \Cris"sum\ (kr?s"s?m),, n.; pl. Crissa (-s?). [NL.; cf. L. crisso to move the haunches.] (Zool.) That part of a bird, or the feathers, surrounding the cloacal opening; the under tail coverts. [1913 Webster]