plunder vs rip off

plunder is a noun but rip off is not a noun.

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

As verbs, rip off is a hypernym of plunder; that is, rip off is a word with a broader meaning than plunder:

Other hypernyms of plunder include rip, steal.

plunder (noun)	rip off (noun)
goods or money obtained illegally

plunder (verb)	rip off (verb)
destroy and strip of its possession	remove by pulling or ripping violently and forcefully
steal goods; take as spoils	take without the owner's consent
plunder (a town) after capture	deprive somebody of something by deceit
take illegally; of intellectual property