A violent, greedy, or ruthless person; a plunderer; (also more generally) a scoundrel.
Origin
Mid 16th century; earliest use found in David Lindsay (c1486–1555), writer and herald. Origin uncertain; perhaps from post-classical Latin robiator, roberator, robator, perhaps influenced in form by its cognate Italian rubatorerobber. With some forms perhaps compare post-classical Latin rabiator someone who rages.