oestrus
/ˈiːstrəs/( <美> estrus)
noun
mass noun
- a recurring period of sexual receptivity and fertility in many female mammals; heat（许多雌性哺乳动物的）发情期, 动情期; 激情：
a mare in oestrus.
发情期的母马。
派生词
oestrous
adjective词源
late 17th cent.: from Greek oistros 'gadfly or frenzy'.