rifle (n.) Look up rifle at Dictionary.com
1775, "portable firearm having a spirally grooved bore," used earlier of the grooves themselves (1751), noun use of rifled (pistol), 1689, from verb meaning "to cut spiral grooves in" (a gun barrel), 1635, probably from Fr. rifler, from O.Fr. rifler "to scratch or groove" (see rifle (v.)).
rifle (v.) Look up rifle at Dictionary.com
"to plunder," 1326 (implied in rifling), from O.Fr. rifler "strip, plunder," lit. "to graze, scratch," probably from a Gmc. source (cf. O.E. geriflian "to wrinkle," O.H.G. riffilon "to tear by rubbing," O.N. rifa "to tear, break").