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guinea pig

American  

noun

  1. a short-eared, tailless rodent of the genus Cavia, usually white, black, and tawny, commonly regarded as the domesticated form of one of the South American wild species of cavy: often used in scientific experiments or kept as a pet.

  2. Informal. the subject of any sort of experiment.

    I've volunteered as a guinea pig in several clinical trials.


guinea pig British  

noun

  1. a domesticated cavy, probably descended from Cavia porcellus, commonly kept as a pet and used in scientific experiments

  2. a person or thing used for experimentation

"Collins English Dictionary — Complete & Unabridged" 2012 Digital Edition © William Collins Sons & Co. Ltd. 1979, 1986 © HarperCollins Publishers 1998, 2000, 2003, 2005, 2006, 2007, 2009, 2012

Etymology

Origin of guinea pig

First recorded in 1655–65

Example Sentences

Examples are provided to illustrate real-world usage of words in context. Any opinions expressed do not reflect the views of Dictionary.com.

He said his shelter was currently housing four dogs, two cats and a Guinea pig.

From Seattle Times • May 1, 2022

Guinea pig meat, known as “cuy” in Ecuador, is typically eaten as a savory dish there and in other South American countries, like Peru and Colombia, where it's often grilled and served whole, per NPR.

From Fox News • Oct. 6, 2019

Amy Sherwood, 33, an echocardiographer at Wrexham Maelor Hospital, was acting as a Guinea pig with a colleague when she spotted the growth.

From BBC • Aug. 14, 2013

Good morning, Dotty Dimple," said Horace: "did my Guinea pig wake you?

From Dotty Dimple Out West by May, Sophie

Like a coal mine, a pearl, a Guinea pig, a drunken man, and a chègre, she supposed an eel was peculiar to the climate, and could be found nowhere but out West.

From Dotty Dimple Out West by May, Sophie