# oestrus

> English word · Noun · IPA /ˈiːstɹəs/

## Definitions
1. A biting fly of the genus Oestrus; a botfly.
2. A bite or sting.
3. A passion or frenzy.
4. A female animal's readiness to mate.

## Etymology
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”).

## Source
Compiled from Wiktionary via kaikki.org (CC BY-SA). Data vintage: 2026-09-03.
Canonical page: https://plainspell.com/en/word/oestrus