: any of various natural steroids (such as estradiol) that are formed from androgen precursors, that are secreted chiefly by the ovaries, placenta, adipose tissue, and testes, and that stimulate the development of female secondary sex characteristics and promote the growth and maintenance of the female reproductive system
also : any of various synthetic or semisynthetic steroids (such as ethinyl estradiol) that mimic the physiological effect of natural estrogens

Examples of estrogen in a Sentence

Recent Examples on the Web
Examples are automatically compiled from online sources to show current usage. Read More Opinions expressed in the examples do not represent those of Merriam-Webster or its editors. Send us feedback.
Women across the country are still struggling to fill prescriptions for estrogen patches. — Berkeley Lovelace Jr, NBC news, 23 Oct. 2026 The very limited research on estrogen facial creams is far less bullish. — Ashley Abramson, Allure, 22 Oct. 2026 With Bosomworth and other practitioners pointing to estrogen’s role, expect fitness apps, wearables and recovery brands to roll out protocols that adjust temperature, duration and timing by menstrual-cycle phase. — Samantha Agate, Miami Herald, 22 Oct. 2026 The meibomian glands, which produce the oil layer of tears, are affected by the drop in estrogen, progesterone and testosterone that begins in perimenopause. — Samantha Agate, Sacbee.com, 21 Oct. 2026 See All Example Sentences for estrogen

Word History

Etymology

estrus + -o- + -gen

Note: The word estrogen was originally a U.S. brand name for an extract of glandular tissue used in the treatment of ovarian dysfunction. Its producer, Parke, Davis and Company, relinquished rights to the name in 1936.

First Known Use

1927, in the meaning defined above

Time Traveler
The first known use of estrogen was in 1927

Browse Nearby Words

Cite this Entry

“Estrogen.” Merriam-Webster.com Dictionary, Merriam-Webster, https://www.merriam-webster.com/dictionary/estrogen. Accessed 25 Oct. 2026.

Kids Definition

estrogen

noun
: a substance that tends to cause the development of secondary sex characteristics in the female and promote the growth and normal functioning of the female reproductive system
estrogenic
ˌes-trə-ˈjen-ik
adjective

Medical Definition

estrogen

noun
variants or chiefly British oestrogen
: any of various natural steroids (as estradiol) that are formed from androgen precursors, that are secreted chiefly by the ovaries, placenta, adipose tissue, and testes, and that stimulate the development of female secondary sex characteristics and promote the growth and maintenance of the female reproductive system
also : any of various synthetic or semisynthetic steroids (as ethinyl estradiol) that mimic the physiological effect of natural estrogens
estrogen-like adjective
an estrogen-like compound
estrogen-like effects

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