estrous cycle phase diestrus estrus metestrus http://purl.bioontology.org/ontology/MESH/D008686 http://purl.obolibrary.org/obo/GO_0060210 https://www.wikidata.org/wiki/Q22299143 The period following estrus during which the phenomena of estrus subside in those animals in which pregnancy or pseudopregnancy does not occur.