Wordnet 3.0
NOUN (1)
1.
(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;
The Collaborative International Dictionary of English v.0.48:
Endometrium \En`do*me"tri*um\, n. [NL., fr. Gr. 'e`ndon within +
mh`tra the womb.] (Anat.)
The membrane lining the inner surface of the uterus, or womb.
[1913 Webster]
WordNet (r) 3.0 (2006):
endometrium
n 1: (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