WORD ORIGIN noun . Zoology Also es·trum , [ es-tr uh m] /ˈɛs trəm/ oestrus. the period of heat or rut; the period of maximum sexual receptivity of the female. Origin of estrus 1885–90;
Latin oestrus oestrus Related forms es·tru·al , [ es-troo- uh l] /ˈɛs tru əl/ adjective
Based on the Random House Unabridged Dictionary, © Random House, Inc. 2019
British Dictionary definitions for estrus Derived Forms estrous, adjective
Collins English Dictionary - Complete & Unabridged 2012 Digital Edition
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Word Origin and History for estrus n.
1850, "frenzied passion," from Latin
oestrus "frenzy, gadfly," from Greek oistros "gadfly, breeze, sting, mad impulse," perhaps from a PIE *eis, forming words denoting passion (cf. Avestan aešma- "anger," Lithuanian aistra "violent passion," Latin ira "anger"). First attested 1890 with specific meaning "rut in animals, heat." Earliest use (1690s) was for "a gadfly." Related: Estrous (1900).
Online Etymology Dictionary, © 2010 Douglas Harper
n. The periodic state of sexual excitement in the female of most mammals, excluding humans, that immediately precedes ovulation and during which the female is most receptive to mating; heat.
The American Heritage® Stedman's Medical Dictionary
Copyright © 2002, 2001, 1995 by Houghton Mifflin Company. Published by Houghton Mifflin Company.
A regularly recurring period in female mammals other than humans during which the animal is sexually receptive. Estrus occurs around the time of ovulation. Also called heat
The American Heritage® Science Dictionary
Copyright © 2011. Published by Houghton Mifflin Harcourt Publishing Company. All rights reserved.