1. a recurring period of sexual receptivity and fertility in female mammals, during which ovulation occurs and the animal is capable of breeding.
Usage: Also spelled 'oestrus' in British English.; Used in biology and veterinary medicine.

Examples

• The veterinarian explained that the dog enters estrus twice a year.
• During estrus, female mammals display behavioral and physiological changes.
• Farmers monitor their cattle for signs of estrus to plan breeding.
• The hormone cycle of estrus is regulated by estrogen and progesterone.
• Many wild animals have a specific estrus season tied to environmental conditions.