noun.
the mucous membrane that lines the uterus in mammals and in which fertilizedeggs are implanted
WordNet 3.0 Copyright 2006 by Princeton University. All rights reserved.
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