An Etymological Dictionary of the German Language/Annotated/Waffe
Waffe, feminine, ‘weapon,’ from the equivalent Middle High German waffen, wâfen, Old High German waffan, wâfan, neuter, ‘weapon, sword, armour’; corresponding to Gothic wépna, neuter plural, ‘weapons,’ Anglo-Saxon wœ̂pn, English weapon, Dutch wapen. Compare also Wappen. Teutonic wêpno- (wapono-) assumes a Teutonic wêbono- (wobono-); its connection with the equivalent Greek ὅπλον (literally ‘utensil’) is conceivable by assuming a double root, wop, wob. Whether this root is identical with the Sanscrit root vap, ‘to scatter, sow,’ in which case ‘missile’ would be the primary meaning of Waffe, is uncertain.