tes·​tos·​ter·​one te-ˈstä-stə-ˌrōn How to pronounce testosterone (audio)
: a hormone that is a hydroxy steroid ketone C19H28O2 produced especially by the testes or made synthetically and that is responsible for inducing and maintaining male secondary sex characters
: qualities (such as brawn and aggressiveness) usually associated with males : manliness

Example Sentences

Recent Examples on the Web Unlike track and field, transgender women would not have to lower their testosterone levels to become eligible. Jeré Longman, New York Times, 20 Feb. 2023 As recently as 20 years ago, even men ages 15 to 39 had testosterone levels that were 20 percent higher. Andrew Zaleski, Men's Health, 20 Feb. 2023 And, as is expected, my testosterone levels are almost at 0. Dr. Keith Roach, oregonlive, 9 Feb. 2023 The rule follows the International Surfing Association's policy that dictates that transgender women may compete in the female category if their testosterone level is less than a certain amount for 12 months. Rebecca Aizin, Peoplemag, 7 Feb. 2023 Some transgender men and nonbinary people opt for testosterone treatments. Laken Brooks, Forbes, 26 Dec. 2021 Clinical studies have shown that eating soy does not reduce sperm count or lower testosterone levels. Bryant Stamford, The Courier-Journal, 27 Jan. 2023 Physical conditions like heart disease, high blood pressure, obesity, and low testosterone levels can all contribute to ED. Amber Smith, Discover Magazine, 15 Jan. 2023 Worrying effects may include behavioral problems and lower testosterone levels in boys and lower thyroid hormone levels and preterm births for women. A. J. Jacobs, New York Times, 11 Jan. 2023 See More

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

Word History


borrowed from German Testosteron, from Latin testēs testes + German -o- -o-- + -steron -sterone

Note: The name was introduced by the Hungarian pharmacologists Karoly Gyula David (1905-45) and János Freud (1901-48), the Dutch endocrinologist Elisabeth Dingemanse (1886-1952), and the German-born Dutch physician and pharmacologist Ernst Laqueur (1880-1947) (all affiliated with the Pharmaco-Therapeutic Laboratory of the University of Amsterdam) in "Über krystallinisches männliches Hormon aus Hoden (Testosteron), wirksamer als aus Harn oder aus Cholesterin bereitetes Androsteron," Zeitschrift für physiologische Chemie, Band 233 (1935), pp. 281-83

First Known Use

1935, in the meaning defined at sense 1

Time Traveler
The first known use of testosterone was in 1935

Dictionary Entries Near testosterone

Cite this Entry

“Testosterone.” Merriam-Webster.com Dictionary, Merriam-Webster, https://www.merriam-webster.com/dictionary/testosterone. Accessed 28 Mar. 2023.

Kids Definition


tes·​tos·​ter·​one te-ˈstäs-tə-ˌrōn How to pronounce testosterone (audio)
: a male hormone produced by the testes that causes the development of the male reproductive system and secondary sex characteristics

Medical Definition


tes·​tos·​ter·​one te-ˈstäs-tə-ˌrōn How to pronounce testosterone (audio)
: a male hormone that is a crystalline hydroxy steroid ketone C19H28O2 produced primarily by the testes or made synthetically and that is the main androgen responsible for inducing and maintaining male secondary sex characteristics see androgel, axiron

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