TIL cloaca

[New Latin, from Latin] : the common chamber into which the intestinal and urogenital tracts discharge especially in monotreme mammals, birds, reptiles, amphibians, and elasmobranch fishes also : a comparable chamber of an invertebrate

: the enlarged terminal part of the posterior embryonic digestive tract of a mammal that gives rise to the rectum, upper anal canal, and urogenital sinus