proestrogen pro·es·tro·gen (prō-ěs'trə-jən)
n.
A precursor of estrogen that becomes an active hormone only after it has been metabolized.
| the offspring of a zebra and a donkey. |
| a calculus or concretion found in the stomach or intestines of certain animals, esp. ruminants, formerly reputed to be an effective remedy for poison. |
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