uterus

noun

uter·​us ˈyü-tə-rəs 

ˈyü-trəs

plural uteri ˈyü-tə-ˌrī  or uteruses

1

: a muscular organ of the female mammal for containing and usually for nourishing the young during development prior to birth

called also womb

2

: a structure in some lower animals analogous to the uterus in which eggs or young develop

Examples of uterus in a Sentence

Recent Examples on the Web

The low hormone levels signal your uterus to shed its lining and begin menstruation.9 Hormonal forms of birth control contain synthetic versions of estrogen and progesterone hormones that mimic your natural hormones. —Femi Aremu, Verywell Health, 30 Apr. 2025

Such hormones are responsible for regulating your menstrual cycle, which is the cycle during which your ovaries produce an egg or eggs and your uterus gets ready for the possible implantation of an egg if that egg gets fertilized. —Bruce Y. Lee, Forbes.com, 27 Apr. 2025

Its initial genesis is not totally clear—but one prominent theory suggests that bits of endometrium (the inside lining of the uterus) shed during menstruation can flow backward through the fallopian tubes and leak into the pelvis. —Erica Sloan, SELF, 25 Apr. 2025

Endometriosis is a chronic condition in which endometrial-like tissue (tissue similar to the lining of the uterus) grows outside the uterus. —Sherri Gordon, Health, 17 Apr. 2025

Word History

Etymology

Middle English, from Latin, belly, womb; probably akin to Greek hoderos belly, Sanskrit udara

First Known Use

14th century, in the meaning defined at sense 1

Kids Definition

uterus

noun

uter·​us ˈyüt-ə-rəs 

plural uteruses or uteri -ˌrī 

: the muscular organ of a female mammal in which the young develop before birth

called also womb

Medical Definition

uterus

noun

uter·​us ˈyüt-ə-rəs 

plural uteri -ˌrī  also uteruses

: an organ in female mammals for containing and usually for nourishing the young during development prior to birth that consists of a greatly modified and enlarged section of an oviduct (as in rodents and marsupials) or of the two oviducts united (as in the higher primates including humans), that has thick walls consisting of an outer serous layer, a very thick middle layer of smooth muscle, and an inner mucous layer containing numerous glands, and that during pregnancy undergoes great increase in size and change in the condition of its walls

called also womb

see cervix sense 2a, corpus uteri, endometrium, fundus sense c, myometrium, perimetrium