endometrial vs endometrium

endometrial is not a noun while endometrium is a noun.

Word	Noun	Adjective	Verb	Adverb
endometrial	No	Yes	No	No
endometrium	Yes	No	No	No

endometrial (noun)	endometrium (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

endometrial (adjective)	endometrium (adjective)
of or relating to the endometrium