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
    n 1: any of several herbivorous leaping marsupials of Australia
         and New Guinea having large powerful hind legs and a long
         thick tail

Moby Thesaurus II by Grady Ward, 1.0:

278 Moby Thesaurus words for "kangaroo":
   Angora goat, Arctic fox, Belgian hare, Caffre cat, Indian buffalo,
   Kodiak bear, Virginia deer, aardvark, aardwolf, alpaca, anteater,
   antelope, antelope chipmunk, aoudad, apar, armadillo, ass, aurochs,
   badger, bandicoot, bassarisk, bat, bear, beaver, bettong,
   binturong, bison, black bear, black buck, black cat, black fox,
   black sheep, blue fox, bobcat, broad jumper, brown bear,
   brush deer, brush wolf, bucking bronco, buckjumper, buffalo,
   buffalo wolf, burro, burro deer, cachalot, camel, camelopard,
   capybara, carabao, caribou, carpincho, cat, cat-a-mountain,
   catamount, cattalo, cavy, chamois, cheetah, chevrotain, chinchilla,
   chipmunk, cinnamon bear, coon, coon cat, cotton mouse, cotton rat,
   cougar, cow, coyote, coypu, deer, deer tiger, dingo, dog, donkey,
   dormouse, dromedary, echidna, eland, elephant, elk, ermine, eyra,
   fallow deer, ferret, field mouse, fisher, fitch, flea,
   flying phalanger, foumart, fox, fox squirrel, frog, gazelle,
   gemsbok, genet, giraffe, glutton, gnu, gnu goat, goat,
   goat antelope, gopher, grasshopper, grizzly bear, ground squirrel,
   groundhog, guanaco, guinea pig, hamster, hare, harnessed antelope,
   hartebeest, hedgehog, high jumper, hippopotamus, hog, hopper,
   horse, hurdle racer, hurdler, hyena, hyrax, ibex, jackal, jackass,
   jackrabbit, jaguar, jaguarundi, jerboa, jerboa kangaroo, jumper,
   jumping bean, jumping jack, kaama, kangaroo mouse, kangaroo rat,
   karakul, kinkajou, kit fox, koala, lapin, leaper, lemming, leopard,
   leopard cat, lion, llama, lynx, mammoth, mara, marmot, marten,
   mastodon, meerkat, mink, mole, mongoose, moose, mouflon,
   mountain goat, mountain lion, mountain sheep, mouse, mule,
   mule deer, muntjac, musk deer, musk hog, musk-ox, muskrat,
   musquash, nilgai, nutria, ocelot, okapi, onager, oont, opossum,
   otter, ounce, ox, pack rat, painter, panda, pangolin, panther,
   peccary, peludo, phalanger, pig, pine mouse, platypus,
   pocket gopher, pocket mouse, pocket rat, polar bear, polar fox,
   pole vaulter, polecat, porcupine, possum, pouched rat, poyou,
   prairie dog, prairie wolf, pronghorn, puma, rabbit, raccoon, rat,
   red deer, red squirrel, reindeer, rhinoceros, roe, roe deer,
   roebuck, sable, salmon, serval, sheep, shrew, shrew mole, sika,
   silver fox, skunk, sloth, snowshoe rabbit, springbok, squirrel,
   stag, stoat, sunfisher, suslik, swamp rabbit, swine, takin,
   tamandua, tamarin, tapir, tarpan, tatou, tatou peba, tatouay,
   tiger, tiger cat, timber topper, timber wolf, tree shrew, urus,
   vaulter, vole, wallaby, warthog, water buffalo, waterbuck, weasel,
   wharf rat, whistler, white fox, wild ass, wild boar, wild goat,
   wild ox, wildcat, wildebeest, wolf, wolverine, wombat, wood rat,
   woodchuck, woolly mammoth, yak, zebra, zebu, zoril