<chemical> 3-hydroxyestra-1,3,5(10),6,8-pentaen-17-one. A naturally occurring steroid with oestrogenic activity obtained from the urine of pregnant mares. ... Chemical name: Estra-1,3,5,7,9-pentaen-17-one, 3-hydroxy- ... (12 Dec 1998) ... 
Type: Term Pronunciation: ek′wi-len′in Definitions: 1. A weakly estrogenic steroid isolated from urine of pregnant mares.