guinea pig

noun

1

: a small stout-bodied short-eared tailless domesticated rodent (Cavia porcellus) of South American origin often kept as a pet and widely used in biological research

called also cavy

2

: a subject of research, experimentation, or testing

Examples of guinea pig in a Sentence

He volunteered to act as a guinea pig in the experiment.

Recent Examples on the Web

That is because cats see guinea pigs as big hairy mice, which is their favorite prey. —Nina Turner, Newsweek, 30 Oct. 2024

By creating digital twins of cancer patients, they could be used as virtual guinea pigs, recreating clinical trials to compare the effectiveness of treatments and predict how a patient is likely to respond. —New Atlas, 28 Oct. 2024

Alien Invasion Turn your guinea pig into an Uber for extraterrestrials with this playful costume secured by a velcro strap. —Kelli Bender, People.com, 11 Oct. 2024

Featured Gallery Rangeland Elementary has four guinea pigs named Dexter, Diego, Coco Chanel and Vera Wang. —Ray Padilla, The Courier-Journal, 10 Sep. 2024

Word History

First Known Use

1664, in the meaning defined at sense 1

Kids Definition

guinea pig

noun

1

: a small stocky rodent with short ears and a very short tail that is often kept as a pet and is used in biological research

2

: a person or thing experimented on

Medical Definition

guinea pig

noun

guin·​ea pig ˈgin-ē-ˌ 

: a small stout-bodied short-eared nearly tailless domesticated rodent of the genus Cavia (C. cobaya) often kept as a pet and widely used in biological research

called also cavy