air passage vs airway

air passage and airway both are nouns.

Word	Noun	Adjective	Verb	Adverb
air passage	Yes	No	No	No
airway	Yes	No	No	No

As nouns, air passage and airway are synonyms defined as:

Other synonyms of air passage include air duct.

air passage (noun)	airway (noun)
a duct that provides ventilation (as in mines)	a commercial enterprise that provides scheduled flights for passengers
	a duct that provides ventilation (as in mines)
	the passages through which air enters and leaves the body
	a designated route followed by airplanes in flying from one airport to another