air duct vs airway

air duct and airway both are nouns.

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

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

Other synonyms of air duct include air passage.

air duct (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