noun. a naturally occurring weak estrogenic hormone secreted by the mammalian ovary; synthesized (trade name Estronol) and used to treat estrogen deficiency.
1. Noun, singular or mass Estradiol, estriol and estrone, the three most important estrogens, are particularly important and have a direct influence on the reproductive system, points out the U.S. National Library of Medicine. 2. Adverb Adipose tissue produces estrone, a hormone that supports the reproductive function.