rip off vs bunk

rip off is not a noun while bunk is a noun.

Word	Noun	Adjective	Verb	Adverb
rip off	No	No	Yes	No
bunk	Yes	No	Yes	No

As verbs, bunk is a hyponym of rip off; that is, bunk is a word with a more specific, narrower meaning than rip off:

rip off (noun)	bunk (noun)
	a bed on a ship or train; usually in tiers
	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

rip off (verb)	bunk (verb)
remove by pulling or ripping violently and forcefully	flee; take to one's heels; cut and run
take without the owner's consent	provide with a bunk
deprive somebody of something by deceit	avoid paying