airway vs upcast

airway and upcast both are nouns.

Word	Noun	Adjective	Verb	Adverb
airway	Yes	No	No	No
upcast	Yes	No	No	No

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

airway: a duct that provides ventilation (as in mines)
upcast: air passage consisting of a ventilation shaft through which air leaves a mine

airway (noun)	upcast (noun)
a commercial enterprise that provides scheduled flights for passengers	air passage consisting of a ventilation shaft through which air leaves a mine
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