What does cavy mean?
A cavy is any of several stout, tailless rodents native to South America, belonging chiefly to the genus Cavia and its relatives within the family Caviidae. Cavies have compact bodies, short ears, and continuously growing teeth suited to a plant-based diet, and they inhabit grasslands, savannas, and rocky areas across the continent. The word matters most because one of these animals — the domestic guinea pig — has been bred for centuries as a household pet and laboratory animal, yet most people never learn that "cavy" is the proper zoological name for the group it belongs to. In everyday speech, "guinea pig" dominates, so "cavy" carries a slightly formal, specialist flavor: it is the term of choice among breeders, exhibitors at cavy shows, and scientists writing about South American fauna. Its plural, cavies, follows the regular English pattern of changing y to ies.
Any of several short-tailed, herbivorous South American rodents of the genus Cavia or the family Caviidae, including the wild ancestor of the domestic guinea pig.
"Biologists studied the foraging habits of wild cavies on the Argentine pampas."
A domestic guinea pig, especially when referred to formally by breeders or fanciers.
"She keeps three cavies and shows them at regional competitions."
The plural follows the standard English pattern of replacing final -y with -ies after a consonant. The singular "a cavy" is common when referring to one animal.
"Wild cavies are social animals that often live in small groups."
The guinea pig isn't from Guinea and isn't a pig — but it is a cavy, a word borrowed from the Indigenous peoples of Guyana.
Reviewed by Deb Chak, Editor. AI-assisted content curated by RJS Tech Solutions LLP.
Etymology of cavy
The word "cavy" entered English in the mid-17th century, borrowed through French "cabiai" from a Carib (Galibi) word for the animal recorded in the Guianas region of South America. It thus joins a small set of English words of indigenous South American origin. The same indigenous root also underlies "capybara," the name of the world's largest rodent, whose taxonomic family (Caviidae's larger grouping, Cavioidea) bears a related form.
How cavy is actually used
"Cavy" is a somewhat technical term used mainly by zoologists, breeders, and fanciers; everyday speakers almost always say "guinea pig" for the pet animal. The standard plural is irregular: "cavies."
Easily confused with cavy
"Guinea pig" refers specifically to the domesticated species kept as a pet, while "cavy" is the broader term covering both the wild genus Cavia rodents and their domesticated descendants.
A capybara is a much larger semi-aquatic South American rodent; despite sharing an indigenous American root in its name, it belongs to a different family than the small cavies.