/ Dictionary / Index C crissum: Meaning and Definition of Find definitions for: cris•sum Pronunciation: (kris'um), [key] — pl. cris•sa the region surrounding the cloacal opening beneath the tail of a bird. the feathers of this region collectively. Random House Unabridged Dictionary, Copyright © 1997, by Random House, Inc., on Infoplease. crisscross crista Related Content Daily Word Quiz: languid Analogy of the Day: Today’s Analogy Spelling Bee: Today’s Spelling Bee Frequently Misspelled Words Frequently Mispronounced Words Easily Confused Words Writing & Language