noun. (pregnancy) the mucous membrane that lines the uterus; thickens under hormonal control and (if pregnancy does not occur) is shed in menstruation; if pregnancy occurs it is shed along with the placenta at parturition.
- mucous membrane
- endo- (English)
Example sentences of the word endometrium
1. Noun, singular or mass
A transvaginal ultrasound is done to take an ultrasound picture of the endometrium lining in the uterus.