lymph vessel vs epithelial duct

lymph vessel and epithelial duct both are nouns.

Word	Noun	Adjective	Verb	Adverb
lymph vessel	Yes	No	No	No
epithelial duct	Yes	No	No	No

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

lymph vessel: a vascular duct that carries lymph which is eventually added to the venous blood circulation
epithelial duct: a bodily passage or tube lined with epithelial cells and conveying a secretion or other substance

Other hypernyms of lymph vessel include canal, channel, duct.

lymph vessel (noun)	epithelial duct (noun)
a vascular duct that carries lymph which is eventually added to the venous blood circulation	a bodily passage or tube lined with epithelial cells and conveying a secretion or other substance