guinea pig


Definition of guinea pig 

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

And although elephants and rock hyraxes (which resemble guinea pigs) do not have descending testicles, RXFP2 and INSL3 are still intact in both. New York Times, "The Evolutionary Origin of Descending Testicles," 29 June 2018 And some of us out here are just the guinea pigs for that. Mackenzie Schmidt,, "Nicole Curtis Says She Will Keep Fighting for Her Family: ‘Sometimes the Storm Clears the Path’," 10 July 2018 Other pets, such as guinea pigs, baby chicks, and various lizard species, can bring salmonella into the house as well. Tara Smith, SELF, "Why Does It Seem Like Salmonella Is Popping Up in Every Food These Days?," 28 June 2018 And Arizona's government aided the experiment by providing a lax regulatory environment that essentially left patients as guinea pigs, author and investigative reporter John Carreyrou said. Rachel Leingang, azcentral, "Theranos experimented on Arizonans with faulty blood tests, book says," 7 June 2018 Casper’s Nap Pillow is a small pillow that’s a little bit longer than a guinea pig (yes, that is how Casper is displaying scale in its promo photos). Don Reisinger, Fortune, "The Casper Nap Pillow Is Your Next $35 Travel Companion," 5 June 2018 Plus rabbits, guinea pigs, pigeons, a gecko, several quail and a rooster. Heather Knight, San Francisco Chronicle, "Side trip on Muni: just one stop in puppy’s life," 14 May 2018 According to the Florida Times-Union, the animals included a guinea pig, four birds and two rabbits. Fox News, "Man put live animals into trash compactor, authorities say," 5 Apr. 2018 Human guinea pigs are now driving sensor- and camera-laden Teslas, Volvos, and Range Rovers around the Boston area. Aarian Marshall, WIRED, "Tesla's Favorite Autopilot Safety Stat Just Doesn't Hold Up," 4 May 2018

These example sentences are selected automatically from various online news sources to reflect current usage of the word 'guinea pig.' Views expressed in the examples do not represent the opinion of Merriam-Webster or its editors. Send us feedback.

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First Known Use of guinea pig

1664, in the meaning defined at sense 1

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Statistics for guinea pig

Last Updated

6 Nov 2018

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Time Traveler for guinea pig

The first known use of guinea pig was in 1664

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More Definitions for guinea pig

guinea pig


English Language Learners Definition of guinea pig

: a small animal that is often kept as a pet

: a person or thing used for testing something

guinea pig


Kids Definition of guinea pig

: a small stocky South American animal that is a rodent with short ears and a very short tail and is often kept as a pet

guinea pig

guin·​ea pig | \ˈgin-ē-ˌ \

Medical Definition of guinea pig 

: 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

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Comments on guinea pig

What made you want to look up guinea pig? Please tell us where you read or heard it (including the quote, if possible).


playful or foolish behavior

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