rover n.1

Middle English reven "to rob plunder," from Old English reafian "to rob (something from someone), plunder, pillage, take away by force or stealth," from Proto-Germanic *raubōjanan "to rob, deprive of" (source also of Old Frisian ravia, Middle Dutch roven, Dutch rooven, Old High German roubon, German rauben), from PIE *runp- "to break" (see corrupt (adj.)).

Related: Reaved; reaving. Now obsolete or archaic or dialectal only. The old past participle was reft. Also compare bereave. OED reports that the forms reive, rieve, originally Scottish, were sometimes used "when the reference is to the taking of goods or cattle by force," hence reiver, reiver, etc., e.g. "The Reivers," Faulkner's novel.

also reiver, Middle English rever, revere, "robber, destroyer, plunderer," Old English reafere "plundering forager," agent noun from reafian "to rob, plunder" (see reave (v.)). Similar formation in Old Frisian ravere, Middle Dutch rover, Dutch roover, Old High German roubari, German Räuber. Middle English rēverie (c. 1300) meant "robbery, plundering."

"to wander with no fixed destination," 1530s (earliest sense was "to shoot arrows at a mark selected at pleasure or at random," late 15c.); possibly a Midlands dialectal variant of northern English and Scottish rave "to wander, stray," from Middle English raven "to wander, stray, rove" (late 14c.). This is probably from Old Norse rafa "to wander, rove." Or it might be from Old French raver, a late 15c. variant of resver "to stray" (see rave (v.)). Influenced by rover, if not in part a back-formation from it. Related: Roved; roving.