a gregarious burrowing hystricomorph rodent, Lagostomus maximus, of southern South America, similar to but larger than the chinchillas: family Chinchillidae
2. mountain viscacha
Word origin
C17: from Spanish, from Quechuan wiskácha
viscacha in American English
(vɪsˈkɑtʃə)
noun
any of two genera (Lagostomus and Lagidium, family Chinchillidae) of burrowing South American rodents that live in small colonies