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the recurrent, restricted period of sexual receptivity in female mammals other than human females, marked by intense sexual urge. See also estrous cycle. Called also estruation, estrum, and heat. adj., adj es´trual, es´trous.


That portion or phase of the sexual cycle of female animals characterized by willingness to permit coitus; readily detectable behavioral and other signs are exhibited by animals during this period.
Synonym(s): estruation, heat (2) , oestrus.
[G. oistros, mad desire]


The sexually fertile period in female mammals. In lay terminology, the period of heat.
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