sword (n.)

"offensive weapon consisting of an edged blade fitted to a hilt, used for cutting or thrusting," Middle English sword, from Old English sweord, swyrd (West Saxon), sword (Northumbrian) "sword," from Proto-Germanic *swerdam (source also of Old Saxon, Old Frisian swerd, Old Norse sverð, Swedish svärd, Middle Dutch swaert, Dutch zwaard, Old High German swert, German Schwert "a sword"). This is held to be related to Old High German sweran "to hurt," from *swertha-, literally "the cutting weapon," from PIE root *swer- "to cut, pierce."

From late Old English figuratively as "military power; conflict, war." The contrastive pairing with plowshare is an image from the Old Testament (Isaiah ii.4, Micah iv.3). Phrase put (originally do) to the sword "kill, slaughter" is recorded from mid-14c.

An older Germanic word for the weapon is found in Old Saxon heoru, Gothic hairus "a sword."

Sword-arm "the arm with which a sword is wielded" is from 1690s; sword-fight "a combat with swords" is from 1620s. Sword-dance, one in which a naked sword forms some part, is by c. 1600.