testosterone

UK: /tɛˈstɒstərəʊn/ US: /tɛˈstɑstəˌroʊn/ ,(tes tos′tə rōn′)

WordReference Random House Learner's Dictionary of American English © 2026

tes•tos•ter•one /tɛˈstɑstəˌroʊn/   n. [uncountable]

1. Biochemistry the sex hormone released by the testes that stimulates the development of male sex organs, hair growth, and sperm development.

WordReference Random House Unabridged Dictionary of American English © 2026

tes•tos•ter•one  (tes tos′tə rōn′), n. 

1. Biochemistry the sex hormone, C₁₉H₂₈O₂, secreted by the testes, that stimulates the development of male sex organs, secondary sexual traits, and sperm.
2. Drugs [Pharm.] a commercially prepared form of this compound, originally isolated from bull's testes and now also produced synthetically, used in medicine chiefly for treatment of testosterone deficiency and for certain gynecological conditions.

• testo- (combining form of testis) + ster(ol) + -one 1930–35

Collins Concise English Dictionary © HarperCollins Publishers::

testosterone / tɛsˈtɒstəˌrəʊn/ noun

1. a potent steroid hormone secreted mainly by the testes. It can be extracted from the testes of animals or synthesized and used to treat androgen deficiency or promote anabolism. Formula: C₁₉H₂₈O₂

Etymology: 20th Century: from testis + sterol + -one