tes·tis | \ˈte-stəs \
plural testes\ˈte-ˌstēz \

Definition of testis 

: 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

Examples of testis in a Sentence

Recent Examples on the Web

Source of prostates and testes, muscles and machismo, chest hair, and according to some, even math skills. Diana Gitig, Ars Technica, "Testosterone may protect men from autoimmune diseases," 2 Feb. 2018 His team interacts directly with farmers and breeders, from small-scale operations to major corporations, and maintains the NCGRP’s collection, which includes 800,000 samples—semen, embryos, ovaries, testes, blood—from 25,000 different animals. Sena Christian, Newsweek, "Breakfast in Post-Apocalypse America: Inside Colorado's Fort Knox of Food," 19 Nov. 2015 This also meant that testicondy evolved after afrotherians split from other placental mammals, about 100 million years ago, which suggests the common ancestor of all mammals did indeed lower their testes, Dr. Hiller said. New York Times, "The Evolutionary Origin of Descending Testicles," 29 June 2018 Within a matter of days, the new female will also begin to undergo some pretty stark physical transformations, growing rapidly in size as her testes recede back into her body. Katherine J. Wu, Smithsonian, "Alternatives to Heterosexual Pairings, Brought to You By Non-Human Animals," 28 June 2018 This gene indirectly turns on another gene called Sox9, which kick-starts the construction of the testes. Elizabeth Pennisi, Science | AAAS, "The little piece of DNA that makes girls boys," 14 June 2018 Some have the male chromosome but no testes, for example, and doctors can figure out the reason for these abnormalities in fewer than half of all cases. Elizabeth Pennisi, Science | AAAS, "The little piece of DNA that makes girls boys," 14 June 2018 For the transplant, the donor's testes were first removed because of what the doctors said were complicated ethical issues, in particular the potential ability to father children with another man's genetic material. Eli Rosenberg, ajc, "Veteran receives penis, scrotum transplant in surgery doctors hail as a medical first," 25 Apr. 2018 First, up to 10% of mumps infections in teenagers or adults may cause severe complications, including deafness, meningitis and involvement of the testes or ovaries. Susan Scutti, CNN, "Mumps outbreaks linked to waning vaccine protection, study says," 21 Mar. 2018

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.

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First Known Use of testis

1650, in the meaning defined above

History and Etymology for testis

Latin, witness, testis

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Last Updated

7 Sep 2018

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Time Traveler for testis

The first known use of testis was in 1650

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More Definitions for testis


tes·tis | \ˈte-stəs \
plural testes\ˈte-ˌstēz \

Kids Definition of testis

: a male reproductive gland that produces sperm


tes·tis | \ˈtes-təs \
plural testes\ˈtes-ˌtēz \

Medical Definition of testis 

: 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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Britannica.com: Encyclopedia article about testis

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