Guinea pig


(1)   Stout-bodied nearly tailless domesticated cavy; often kept as a pet and widely used in research
(2)   A person who is subjected to experimental or other observational procedures; someone who is an object of investigation
"The subjects for this investigation were selected randomly"
"The cases that we studied were drawn from two different communities"


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 ; guinea pigs were referred to as "pig coneys" in Edward Topsell's 1607 treatise on quadrupeds.


  1. A tailless rodent of the Cavia genus, with short ears and larger than a hamster; the species Cavia porcellus is often kept as a pet.
  2. A person who volunteers for an experiment or to try anything new; an experimental subject (from the use of the rodent in laboratory experiments).
    Would you like to be the guinea pig for our new product concept?