(from the article `mammal`) If fertilization and implantation do not occur, a phase termed metestrus ensues, in which the reproductive tract assumes its normal condition. ...
Short period following estrus during which the phenomena of estrus subside in those animals in which pseudopregnancy does not occur. Does not apply to humans. ... (12 Dec 1998) ... 
Type: Term Pronunciation: met-es′trŭs, -trŭm Definitions: 1. The period between estrus and diestrus in the estrous cycle.
In the estrus cycle, the period of subsidence of follicular activity that follows estrus ("heat").