passageway vs tunnel

passageway and tunnel both are nouns.

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

As nouns, tunnel is a hyponym of passageway; that is, tunnel is a word with a more specific, narrower meaning than passageway:

passageway: a passage between rooms or between buildings
tunnel: a passageway through or under something, usually underground (especially one for trains or cars)

Other hyponyms of passageway include aisle, gangway, arcade, areaway, corridor, drift, gallery, heading, gangway, gate, shaft, walk-through.

passageway (noun)	tunnel (noun)
a passage between rooms or between buildings	a passageway through or under something, usually underground (especially one for trains or cars)
a path or channel or duct through or along which something may pass	a hole made by an animal, usually for shelter

passageway (verb)	tunnel (verb)
	force a way through
	move through by or as by digging