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
Examples are automatically compiled from online sources to show current usage. Read More Opinions expressed in the examples do not represent those of Merriam-Webster or its editors. Send us feedback.
Also listed on the website as available for adoption are two rabbits, six guinea pigs and eight cats. Marcus D. Smith, Sacramento Bee, 18 Jan. 2025 More:Daddy Days: Christmas with the family 5 – Getting a guinea pig. Caleb Harris, Austin American-Statesman, 26 Dec. 2024 While both series feature a guinea pig, the spinoff also includes a bunny and a snake instead of a turtle and a duck. Sari Hitchins, Parents, 20 Nov. 2024 The awkwardness of semi-estrangement melts away instantly when Ingrid visits the hospital and Martha explains that she’s agreed to be a guinea pig in an experimental treatment for her Stage 3 cervical cancer. David Rooney, The Hollywood Reporter, 2 Sep. 2024 See all Example Sentences for guinea pig 

Word History

First Known Use

1664, in the meaning defined at sense 1

Time Traveler
The first known use of guinea pig was in 1664

Dictionary Entries Near guinea pig

Cite this Entry

“Guinea pig.” Merriam-Webster.com Dictionary, Merriam-Webster, https://www.merriam-webster.com/dictionary/guinea%20pig. Accessed 22 Jan. 2025.

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 How to pronounce guinea pig (audio)
: 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

More from Merriam-Webster on guinea pig

Last Updated: - Updated example sentences
Love words? Need even more definitions?

Subscribe to America's largest dictionary and get thousands more definitions and advanced search—ad free!