Source : Webster's Revised Unabridged Dictionary (1913)

Viscacha \Vis*ca"cha\, Viz-cacha \Viz-ca"cha\, n. [Sp.]
   (Zo["o]l.)
   A large burrowing South American rodent ({Lagostomus
   trichodactylus}) allied to the chinchillas, but much larger.
   Its fur is soft and rather long, mottled gray above, white or
   yellowish white beneath. There is a white band across the
   muzzle, and a dark band on each cheek. It inhabits grassy
   plains, and is noted for its extensive burrows and for
   heaping up miscellaneous articles at the mouth of its
   burrows. Called also {biscacha}, {bizcacha}, {vischacha},
   {vishatscha}.

Source : WordNet®

viscacha
     n : gregarious burrowing rodent larger than the chinchillas
         [syn: {chinchillon}, {Lagostomus maximus}]