buccaneer vs plunderer

buccaneer and plunderer both are nouns.

Word	Noun	Adjective	Verb	Adverb
buccaneer	Yes	No	Yes	No
plunderer	Yes	No	No	No

As nouns, plunderer is a hypernym of buccaneer; that is, plunderer is a word with a broader meaning than buccaneer:

buccaneer: someone who robs at sea or plunders the land from the sea without having a commission from any sovereign nation
plunderer: someone who takes spoils or plunder (as in war)

Other hypernyms of buccaneer include despoiler, freebooter, looter, pillager, raider, spoiler.

buccaneer (noun)	plunderer (noun)
someone who robs at sea or plunders the land from the sea without having a commission from any sovereign nation	someone who takes spoils or plunder (as in war)

buccaneer (verb)	plunderer (verb)
live like a buccaneer