epididymis vs epithelial duct

epididymis and epithelial duct both are nouns.

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

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

epididymis: a convoluted tubule in each testis; carries sperm to vas deferens
epithelial duct: a bodily passage or tube lined with epithelial cells and conveying a secretion or other substance

Other hypernyms of epididymis include canal, channel, duct.

epididymis (noun)	epithelial duct (noun)
a convoluted tubule in each testis; carries sperm to vas deferens	a bodily passage or tube lined with epithelial cells and conveying a secretion or other substance