belonging to the group of animals that carry their young in a pocket of skin called a pouch
any animal that carries its young in a pocket of skin (called a pouch) on the mother’s stomach. Kangaroos and koalas are marsupials. 有袋类动物（如袋鼠和树袋熊） 
Word Originlate 17th cent. (in the sense ‘resembling a pouch’): from modern Latin marsupialis, via Latin from Greek marsupion ‘pouch’, diminutive of marsipos ‘purse’.
