- (n.) Any one of numerous species of jumping marsupials of the family Macropodidae. They inhabit Australia, New Guinea, and adjacent islands, They have long and strong hind legs and a large tail, while the fore legs are comparatively short and feeble. The giant kangaroo (Macropus major) is the largest species, sometimes becoming twelve or fourteen feet in total length. The tree kangaroos, belonging to the genus Dendrolagus, live in trees; the rock kangaroos, of the genus Petrogale, inhabit rocky situations; and the brush kangaroos, of the genus Halmaturus, inhabit wooded districts. See Wallaby.