guinea pig

guinea pig

NOUN

• 1A tailless South American rodent of the cavy family. Originally raised for food, it no longer occurs in the wild and is now typically kept as a pet or for laboratory research.

  Cavia porcellus, family Caviidae
• 2A person or thing used as a subject for experiment.

  ‘we were used as guinea pigs to test the effects of radiation on human beings’

  ‘the school is a guinea pig for the national initiative’

Origin

Mid 17th century: from Guinea + pig; the term Guinea was probably a designation for an unknown distant country. Use in guinea pig (sense 2) arose in the 1920s in reference to the animal's use in laboratory research.