C0751500 (krĭs′əm)n.pl.cris·sa(krĭs′ə) The feathers or area under the tail of a bird surrounding the cloacal opening.[New Latin, from Latin crīsāre, crissāre, to move the buttocks during intercourse; see sker- in Indo-European roots.]cris′sal(-əl) adj.EncyclopediaSeecrissum