Definitions

1. adjective

Relating to or denoting the period of sexual receptivity in female mammals, especially those of the order Carnivora, that occurs between periods of quiescence.

“The biologist observed the oestrous behavior of the red foxes in the wild.”

2. noun

A period of sexual receptivity in a female mammal, especially those of the order Carnivora.

“The female cat is currently in oestrous and is ready to mate.”