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

In fact, while millennials and Gen Zers have had more time to learn from Gen X and about saving and investing for retirement on their own, the older generation was the guinea pig for the shift. —Byalicia Adamczyk, Fortune, 11 July 2024

The city itself is a UNESCO World Heritage Site, and visitors can explore Incan temples, sample local delicacies like cuy al horno (or roast guinea pig), and locate themselves centrally for a visit to Machu Picchu. —Hannah Selinger, Travel + Leisure, 9 July 2024

In the meantime, the initial cohort of scientists see themselves as guinea pigs in NSF’s grand new experiment. —science.org, 2 July 2024

Stop quivering like a bunch of nervous guinea pigs and get out of our way. —Matt Bai, Washington Post, 2 July 2024

Word History

First Known Use

1664, in the meaning defined at sense 1

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 

: 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