n.
Pronunciation: ' es- ˌ tr ī - ˌ o ̇ l, e- ' str ī -, - ˌ ō l
Function: noun
Etymology: estr ane + tri- + 1 -ol
Date: 1933
: a relatively weak natural estrogenic hormone that is a glycol C 18 H 24 O 3 found in the body chiefly as a metabolite of estradiol, is the main estrogen secreted by the placenta during pregnancy, and is the estrogen typically found in the urine of pregnant women