passageway vs gangway

passageway and gangway both are nouns.

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

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

passageway: a passage between rooms or between buildings
gangway: passageway between seating areas as in an auditorium or passenger vehicle or between areas of shelves of goods as in stores

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

passageway (noun)	gangway (noun)
a passage between rooms or between buildings	a temporary passageway of planks (as over mud on a building site)
a path or channel or duct through or along which something may pass	a temporary bridge for getting on and off a vessel at dockside
	passageway between seating areas as in an auditorium or passenger vehicle or between areas of shelves of goods as in stores