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
When Bryan Johnson launched his business, Blueprint, the mission was fairly simple: Extend the lifespan of humanity, using the entrepreneur as a guinea pig.
—
Eleanor Pringle, Fortune, 24 July 2025
Still, for those seeking pets with simpler daily routines, Barrett acknowledged that betta fish and guinea pigs can be good alternatives—within limits.
—Melissa Fleur Afshar, MSNBC Newsweek, 21 July 2025
These are complicated concepts, and there's no logical reason to expect a company like McDonald's to solve them by using its workforce as guinea pigs for corporate social experiments.
—Jesse Edwards, MSNBC Newsweek, 27 June 2025
The shelter typically receives 2,000 animals a year, from cats and dogs to rabbits, guinea pigs, hamsters, parakeets, exotic birds, reptiles and chickens.
—Tess Kenny, Chicago Tribune, 12 June 2025
See All Example Sentences for guinea pig
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Eleanor Pringle, Fortune, 24 July 2025
Still, for those seeking pets with simpler daily routines, Barrett acknowledged that betta fish and guinea pigs can be good alternatives—within limits.
—Melissa Fleur Afshar, MSNBC Newsweek, 21 July 2025
These are complicated concepts, and there's no logical reason to expect a company like McDonald's to solve them by using its workforce as guinea pigs for corporate social experiments.
—Jesse Edwards, MSNBC Newsweek, 27 June 2025
The shelter typically receives 2,000 animals a year, from cats and dogs to rabbits, guinea pigs, hamsters, parakeets, exotic birds, reptiles and chickens.
—Tess Kenny, Chicago Tribune, 12 June 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 6 Aug. 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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