Freebooter

(n.) One who plunders or pillages without the authority of national warfare; a member of a predatory band; a pillager; a buccaneer; a sea robber.

Thesaurus Entries

air armada, air force, badman, bogey, bravo, brigand, bummer, combat plane, cutthroat, dacoit, desperado, enemy aircraft, footpad, forager, freebooter, gangster, highwayman, holdup man, hoodlum, looter, mobsman, mobster, pillager, plunderer, racketeer, raider, ravager, sacker, slaunchways, thug, villain