the largest rodent: a pig-sized amphibious hystricomorph, Hydrochoerus hydrochaeris, resembling a guinea pig and inhabiting river banks in Central and South America: family Hydrochoeridae
Word origin
C18: from Portuguese capibara, from Tupi
capybara in American English
(ˌkæpɪˈbɑrə)
noun
any of a family (Hydrochoeridae) of tailless, partially web-footed, South American rodents found in and around lakes and streams: the largest extant rodent, reaching a length of over 1.2 m (c. 4 ft)
Word origin
Port capibara < Tupí kapigwara, lit., one who eats grass