testis

noun

tes·​tis ˈte-stəs 

plural testes ˈte-ˌstēz 

: 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

Signals travel from the brain to the pituitary gland, which tells the testes how much of the hormone to make. — Samantha Agate, Miami Herald, 19 Oct. 2026

Hormones from the brain’s pituitary gland tell the testes to produce testosterone, and a feedback loop keeps levels in balance, according to Harvard Health. — Samantha Agate, Kansas City Star, 19 Oct. 2026

Harvard Health describes how signals from the brain to the pituitary gland normally control testosterone production in the testes, with a feedback loop regulating hormone levels in the blood. — Samantha Agate, Fort Worth Star-Telegram, 19 Oct. 2026

Studies have linked phthalates with reproductive problems, such as genital malformations and undescended testes in baby boys and lower sperm counts and testosterone levels in adult males. — Sandee Lamotte, CNN Money, 28 Aug. 2026

Word History

Etymology

Latin, witness, testis

First Known Use

1650, in the meaning defined above

Rhymes for testis

• pestis
• asbestos
• hephaestus

Kids Definition

testis

noun

tes·​tis ˈtes-təs 

plural testes ˈtes-ˌtēz 

: 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 

plural testes ˈtes-ˌtēz 

: 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