/ Dictionary / Index E estriol: Meaning and Definition of Find definitions for: es•tri•ol Pronunciation: (es'trē-ôl", -ol", -trī-), [key] — n. an estrogenic hormone, CH(OH), occurring in urine during pregnancy. a commercial form of this compound, obtained from human placentas or the urine of pregnant women, used in conditions involving estrogen deficiency. Random House Unabridged Dictionary, Copyright © 1997, by Random House, Inc., on Infoplease. See also: estriol (Thesaurus) estrin estrogen Related Content Daily Word Quiz: fabricate Analogy of the Day: Today’s Analogy Spelling Bee: Today’s Spelling Bee Frequently Misspelled Words Frequently Mispronounced Words Easily Confused Words Writing & Language