estriol

noun

es·​tri·​ol ˈe-ˌstrī-ˌȯl 

e-ˈstrī-,

-ˌōl 

: a relatively weak natural estrogenic hormone that is a glycol C₁₈H₂₄O₃ 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

Examples of estriol in a Sentence

Recent Examples on the Web

Monica Molenaar, Alloy’s co-founder, first discovered estriol while living in the Netherlands. —Micaela English, Flow Space, 27 Aug. 2025

Estrogen is a group of hormones (there are three types: estradiol, estriol, and estrone) that helps regulate the menstrual cycle and has an impact on various parts of the body, including the urinary tract, bones, breasts, skin, heart and blood vessels, pelvic muscles, and the brain. —Fiorella Valdesolo, Vogue, 14 June 2023

Both products feature the hero ingredient estriol, a form of estrogen, as well as a peptide to enhance the firming and smoothing effects. —Emily Burns, Footwear News, 3 Sep. 2019

Word History

Etymology

estrane + tri- + -ol entry 1

First Known Use

1933, in the meaning defined above

Rhymes for estriol

• extraterrestrial
• terrestrial

Medical Definition

estriol

noun

es·​tri·​ol ˈes-ˌtrī-ˌȯl  e-ˈstrī- 

-ˌōl

variants or chiefly British oestriol

ˈē-ˌstrī-ˌȯl  ē-ˈstrī- 

-ˌōl

: a relatively weak natural estrogenic hormone that is a glycol C₁₈H₂₄O₃ 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