testis

noun

tes·​tis ˈte-stəs How to pronounce testis (audio)
plural testes ˈte-ˌstēz How to pronounce testis (audio)
: a typically paired male reproductive gland that produces sperm and secretes testosterone and that in most mammals is contained within the scrotum at sexual maturity

Example Sentences

Recent Examples on the Web And that is on the Y chromosome, there is this SRY, or a testis-determining factor, there’s a gene that causes male differentiation and the production of testes and testosterone. Steven Strogatz, Quanta Magazine, 27 July 2022 At six weeks, the gonad switches on the developmental pathway to become an ovary or a testis. Claire Ainsworth, Scientific American, 22 Oct. 2018 For a study published in Genome Biology, Mehta and his colleagues analyzed gene expression in the brain, eye, heart, kidney, muscle tissue and testis of five cichlid species from East African rivers and lakes. Jason G. Goldman, Scientific American, 23 Apr. 2021 Testosterone, which is produced in abundance by male testes, has been shown to tamp down inflammation. Author: Chris Mooney, Sarah Kaplan, Brady Dennis, Anchorage Daily News, 4 Apr. 2020 The best time to irradiate, the two found, was 5.5 to 5.7 days into the pupal stage, when the adult fly’s ovaries and testes were developing and thus most sensitive to radiation. Sarah Zhang, The Atlantic, 26 May 2020 For example, adult male moths that hailed, as larvae, from a dense population develop particularly large testes. Cordelia Fine, Scientific American, 1 Sep. 2017 Scientists have speculated that its regulation in the testes might partially explain higher ACE2 concentrations in men, and why men are more vulnerable to COVID-19. Fox News, 12 May 2020 While women offer the coronavirus plenty of opportunities to enter their cells, men’s testes may give the virus an extra point of entry. Los Angeles Times, 18 Apr. 2020 See More

These example sentences are selected automatically from various online news sources to reflect current usage of the word 'testis.' Views expressed in the examples do not represent the opinion of Merriam-Webster or its editors. Send us feedback.

Word History

Etymology

Latin, witness, testis

First Known Use

1650, in the meaning defined above

Time Traveler
The first known use of testis was in 1650

Dictionary Entries Near testis

Cite this Entry

“Testis.” Merriam-Webster.com Dictionary, Merriam-Webster, https://www.merriam-webster.com/dictionary/testis. Accessed 9 Dec. 2022.

Kids Definition

testis

noun
tes·​tis ˈtes-təs How to pronounce testis (audio)
plural testes ˈtes-ˌtēz How to pronounce testis (audio)
: an oval-shaped male reproductive gland that produces sperm and secretes testosterone and that in most mammals is contained within the scrotum

Medical Definition

testis

noun
tes·​tis ˈtes-təs How to pronounce testis (audio)
plural testes ˈtes-ˌtēz How to pronounce testis (audio)
: a typically paired male reproductive gland that usually consists largely of seminiferous tubules from the epithelium of which spermatozoa develop, that contains androgen-secreting Leydig cells in the interstitial tissue, that corresponds to the ovary of the female and in craniate vertebrates develops from the genital ridges of the embryo, and that in most mammals descends into the scrotum before the attainment of sexual maturity and in many cases before birth

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