1. Plural of proestrus; the period in the estrous cycle of female mammals that immediately precedes estrus, characterized by physiological and behavioral changes in preparation for mating.
Usage: biology; veterinary medicine; also spelled 'proestri' in some contexts

Examples

• The veterinarian explained that proestruses in dogs typically last about 7 to 10 days.
• During proestruses, female mammals exhibit increased levels of estrogen.
• Researchers studied the hormonal changes occurring across multiple proestruses in the study population.
• The behavioral signs observed during proestruses help breeders predict the optimal time for mating.
• Proestruses are marked by swelling of the vulva and attraction of males in many species.