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estrus Syllabification: es·trus
Pronunciation: /ˈestrəs/
(also estrum or chiefly British oestrus)

Definition of estrus in English:


A recurring period of sexual receptivity and fertility in many female mammals; heat: a mare in estrus
More example sentences
  • ‘When the female is in estrus, breeding bulls that are 35 to 55 years old and in their prime can be many miles away,’ Garstang said.
  • Females have a short estrus period of 3 to 5 days.
  • A beef cow has a 21-day estrous cycle, the period from one estrus, or heat, to the next.


Late 17th century: from Greek oistros 'gadfly or frenzy'.



Pronunciation: /ˈestrəs/
Example sentences
  • Males often have overlapping home ranges and compete for access to estrous females; both males and females are generally solitary.
  • Social rank then determines access to estrous ewes during the rut.
  • Variables included in the model were community size, number of adult males, number of adult females, number of dependent infants, number of estrous females, and rainfall as an approximation for food availability.

Definition of estrus in:

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