hot air vs bunk

hot air and bunk both are nouns.

Word	Noun	Adjective	Verb	Adverb
hot air	Yes	No	No	No
bunk	Yes	No	Yes	No

As nouns, bunk is a hypernym of hot air; that is, bunk is a word with a broader meaning than hot air:

Other hypernyms of hot air include hokum, meaninglessness, nonsense, nonsensicality.

hot air (noun)	bunk (noun)
loud and confused and empty talk	a bed on a ship or train; usually in tiers
air that has been heated and tends to rise	a rough bed (as at a campsite)
	beds built one above the other
	a long trough for feeding cattle
	unacceptable behavior (especially ludicrously false statements)
	a message that seems to convey no meaning

hot air (verb)	bunk (verb)
	flee; take to one's heels; cut and run
	provide with a bunk
	avoid paying