any of various herbivorous leaping marsupial mammals of Australia, New Guinea, and adjacent islands with a small head and large ears, that moves by hopping on its powerful rear legs, with a long thick tail used as a support and in balancing, and small forelegs not used in locomotion;
e.g. Like most marsupials, female kangaroos have a pouch called a marsupium in which joeys, young kangaroos or other marsupials, complete their postnatal growth..