The origin of "guinea" in "guinea pig" is hard to explain. One theory is that the animals were brought to Europe by way of
Guinea, leading people to think they had originated there. "Guinea" was also frequently used in English to refer generally to any far-off, unknown country, and so the name may simply be a colorful reference to the animal's foreignness. Others believe "guinea" may be an alteration of the word
coney (“rabbit”); guinea pigs were referred to as "pig coneys" in Edward Topsell's 1607 treatise on quadrupeds.