The Collaborative International Dictionary of English v.0.48:

kangaroo \kan"ga*roo"\, n. [Said to be the native name.] (Zool.)
   Any one of numerous species of jumping marsupials of the
   family Macropodid[ae]. 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.
   [1913 Webster]

   Kangaroo apple (Bot.), the edible fruit of the Tasmanian
      plant Solanum aviculare.

   Kangaroo grass (Bot.), a perennial Australian forage grass
      (Anthistiria australis).

   Kangaroo hare (Zool.), the jerboa kangaroo. See under
      Jerboa.

   Kangaroo mouse. (Zool.) See Jumping mouse, under
      Jumping.
      [1913 Webster]

WordNet (r) 3.0 (2006):

kangaroo apple
    n 1: Australian annual sometimes cultivated for its racemes of
         purple flowers and edible yellow egg-shaped fruit [syn:
         kangaroo apple, poroporo, Solanum aviculare]