‖n. pl. [ NL., fr. Gr. &unr_; = &unr_; matrix, uterus. ] (Zool.) The subclass of Mammalia which includes the marsupials. See Marsupialia. [ 1913 Webster ]

a. (Zool.) Of or relating to the Didelphia. -- n. One of the Didelphia. [ 1913 Webster ]