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
What about my guinea pig? Just as a cat or dog, small animals — rabbits, guinea pigs, rats, gerbils or hamsters — are vulnerable to the heat, especially if they are kept in an enclosure.
—
Sarah Moore, Freep.com, 24 July 2025
An 18-year-old was shot in his own backyard Police believe the shooter is the victim's neighbor, but no suspects have been named
No arrests have been made
Authorities in Texas are investigating the shooting of a teen who was in his backyard, burying his recently deceased guinea pig.
—Samira Asma-Sadeque, People.com, 18 July 2025
Dax is joined by fellow Greater Cincinnati therapy dogs Elvis and Rosie in the competition, which runs from March 3-April 14 and features pets of all shapes and sizes, from cats and dogs to rats and guinea pigs.
—Grace Tucker, The Enquirer, 2 July 2025
Within weeks, advocates began asking questions about where specifically the rabbits, guinea pigs, rats and hamsters ended up.
—Jeff McDonald, San Diego Union-Tribune, 1 June 2025
See All Example Sentences for guinea pig
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Sarah Moore, Freep.com, 24 July 2025
An 18-year-old was shot in his own backyard Police believe the shooter is the victim's neighbor, but no suspects have been named
No arrests have been made
Authorities in Texas are investigating the shooting of a teen who was in his backyard, burying his recently deceased guinea pig.
—Samira Asma-Sadeque, People.com, 18 July 2025
Dax is joined by fellow Greater Cincinnati therapy dogs Elvis and Rosie in the competition, which runs from March 3-April 14 and features pets of all shapes and sizes, from cats and dogs to rats and guinea pigs.
—Grace Tucker, The Enquirer, 2 July 2025
Within weeks, advocates began asking questions about where specifically the rabbits, guinea pigs, rats and hamsters ended up.
—Jeff McDonald, San Diego Union-Tribune, 1 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 20 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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