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Added 9 October 2026

oestrus

/ˈiːstɹəs/ noun

Latin root: oestrus Wiktionary

noun Definition from WordNet 3.1, Princeton University. Pronunciation from Wiktionary, via Kaikki.org. More about oestrus at Wordnik → Where our words come from →

Applies to nonhuman mammals: a state or period of heightened sexual arousal and activity.
Type genus of the Oestridae: sheep botflies.

Origin

Borrowed from Latin oestrus (“gadfly, sting, frenzy”), from Ancient Greek οἶστρος (oîstros), from Proto-Indo-European *h₁eys-, used to form words denoting passion; see also Latin īra (“anger”), Lithuanian aistra (“violent passion”), Avestan 𐬀𐬈𐬯𐬨𐬀 (aesma, “anger”).

From Wiktionary, via Kaikki.org (CC BY-SA)

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