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
Puerto Rico was also a guinea pig in the development of the birth control pill and in the Agent Orange tests.
—
Carlos Aguilar, Los Angeles Times, 29 Mar. 2025
The hormone estrogen, levels of which surge at puberty and decline in perimenopause, was first identified, in guinea pigs, in 1917; its crystalline form was isolated in 1929, by Edward A. Doisy, the chair of the Department of Biochemistry at St. Louis University’s School of Medicine.
—Rebecca Mead, The New Yorker, 3 Mar. 2025
Under the new Trump White House, though, the U.S. government is being offered up as a guinea pig, McElroy said.
—Kyle Chayka, The New Yorker, 26 Feb. 2025
Always transport cats and small pets (like guinea pigs or bunnies) in pet carriers.
—Geoffrey Eisler, ABC News, 12 Jan. 2025
See All Example Sentences for guinea pig
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Carlos Aguilar, Los Angeles Times, 29 Mar. 2025
The hormone estrogen, levels of which surge at puberty and decline in perimenopause, was first identified, in guinea pigs, in 1917; its crystalline form was isolated in 1929, by Edward A. Doisy, the chair of the Department of Biochemistry at St. Louis University’s School of Medicine.
—Rebecca Mead, The New Yorker, 3 Mar. 2025
Under the new Trump White House, though, the U.S. government is being offered up as a guinea pig, McElroy said.
—Kyle Chayka, The New Yorker, 26 Feb. 2025
Always transport cats and small pets (like guinea pigs or bunnies) in pet carriers.
—Geoffrey Eisler, ABC News, 12 Jan. 2025
See All Example Sentences for guinea pig
Cite this Entry
“Guinea pig.” Merriam-Webster.com Dictionary, Merriam-Webster, https://www.merriam-webster.com/dictionary/guinea%20pig. Accessed 3 Apr. 2025.
Copy CitationMedical 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
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