estrous cycle phase proestrus estrus http://id.loc.gov/authorities/subjects/sh85045017 http://purl.bioontology.org/ontology/MESH/D004971 http://purl.obolibrary.org/obo/GO_0060209 https://en.wikipedia.org/wiki/Estrous_cycle#Estrus https://www.wikidata.org/wiki/Q14877502 The period in the estrous cycle associated with maximum sexual receptivity and fertility in non-primate female mammals. oestrus metestrus The Complete Dictionary of Sexology