Rover
Middle English: from Middle Low German, Middle Dutch rōver, from rōven ‘rob’; related to reave.
wiktionary
From Middle English roven(“to wander, to shoot an arrow randomly”) + -er.
From Middle Dutch roven(“to rob”). Cognate with Danish and Norwegian røver(“robber, thief, highwayman, brigand”), Swedish rövare, German Räuber. Compare the native English word reaver, which is ultimately the same composition.
etymonline
rover (n.1)
"sea-robber, pirate," late 14c. (c. 1300 as a surname), from Middle Dutch rover "robber, predator, plunderer," especially in zeerovere "pirate," literally "sea-robber," from roven "to rob," from Middle Dutch roof "spoil, plunder," related to Old English reaf "spoil, plunder," reafian "to reave" (see reave (v.), and compare reaver).
rover (n.2)
"one who wanders or rambles," especially to a great distance, 1610s, agent noun from rove (v.). Meaning "remote-controlled surface vehicle for extraterrestrial exploration" is from 1970.