freebooter vs looter

freebooter and looter both are nouns.

Word	Noun	Adjective	Verb	Adverb
freebooter	Yes	No	No	No
looter	Yes	No	No	No

As nouns, freebooter and looter are synonyms defined as:

Other synonyms of freebooter include despoiler, pillager, plunderer, raider, spoiler.

freebooter (noun)	looter (noun)
someone who takes spoils or plunder (as in war)	someone who takes spoils or plunder (as in war)