proestrus

noun

pro·​es·​trus (ˌ)prō-ˈe-strəs How to pronounce proestrus (audio)
: a period immediately preceding estrus characterized by preparatory physiological changes

Word History

Etymology

New Latin

First Known Use

1906, in the meaning defined above

Time Traveler
The first known use of proestrus was in 1906

Rhymes for proestrus

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Browse Nearby Words

proepisternum
proestrus
proethical
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Cite this Entry

“Proestrus.” Merriam-Webster.com Dictionary, Merriam-Webster, https://www.merriam-webster.com/dictionary/proestrus. Accessed 3 Nov. 2025.

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Medical Definition

proestrus

noun
pro·​es·​trus -ˈes-trəs How to pronounce proestrus (audio)
variants or proestrum
-ˈes-trəm How to pronounce proestrus (audio)
or chiefly British pro-oestrus or pro-oestrum
-ˈēs- How to pronounce proestrus (audio)
: a preparatory period immediately preceding estrus and characterized by growth of graafian follicles, increased estrogenic activity, and alteration of uterine and vaginal mucosa

More from Merriam-Webster on proestrus

Britannica.com: Encyclopedia article about proestrus

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