What is the meaning of Viz-cacha?

(n.) 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.