fistula vs passageway

fistula and passageway both are nouns.

Word	Noun	Adjective	Verb	Adverb
fistula	Yes	No	No	No
passageway	Yes	No	No	No

As nouns, passageway is a hypernym of fistula; that is, passageway is a word with a broader meaning than fistula:

fistula: an abnormal passage leading from a suppurating cavity to the body surface
passageway: a path or channel or duct through or along which something may pass

Other hypernyms of fistula include passage.

fistula (noun)	passageway (noun)
an abnormal passage leading from a suppurating cavity to the body surface	a passage between rooms or between buildings
a chronic inflammation of the withers of a horse	a path or channel or duct through or along which something may pass