vagina vs epithelial duct

vagina and epithelial duct both are nouns.

Word	Noun	Adjective	Verb	Adverb
vagina	Yes	No	No	No
epithelial duct	Yes	No	No	No

As nouns, epithelial duct is a hypernym of vagina; that is, epithelial duct is a word with a broader meaning than vagina:

vagina: the lower part of the female reproductive tract; a moist canal in female mammals extending from the labia minora to the uterus
epithelial duct: a bodily passage or tube lined with epithelial cells and conveying a secretion or other substance

Other hypernyms of vagina include canal, channel, duct.

vagina (noun)	epithelial duct (noun)
the lower part of the female reproductive tract; a moist canal in female mammals extending from the labia minora to the uterus	a bodily passage or tube lined with epithelial cells and conveying a secretion or other substance