estrus

[es-truh s]
noun Zoology.
  1. Also es·trum [es-truh m] /ˈɛs trəm/, oestrus. the period of heat or rut; the period of maximum sexual receptivity of the female.
  2. estrous cycle.

Origin of estrus

1885–90; < Latin oestrus oestrus
Related formses·tru·al [es-troo-uh l] /ˈɛs tru əl/, adjective
Dictionary.com Unabridged Based on the Random House Unabridged Dictionary, © Random House, Inc. 2018

British Dictionary definitions for estrual

estrus

noun
  1. the usual US spelling of oestrus
Derived Formsestrous, adjective
Collins English Dictionary - Complete & Unabridged 2012 Digital Edition © William Collins Sons & Co. Ltd. 1979, 1986 © HarperCollins Publishers 1998, 2000, 2003, 2005, 2006, 2007, 2009, 2012

Word Origin and History for estrual

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

estrual in Medicine

estrus

n.
  1. 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.

estrual in Science

estrus

[ĕstrəs]
  1. 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.