sword-belt n.

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"), related to Old High German sweran "to hurt," from *swertha-, literally "the cutting weapon," from PIE root *swer- (3) "to cut, pierce."

Contrast with plowshare is 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 it is in Old Saxon heoru, Gothic hairus "a sword."

Old English belt "belt; girdle; broad, flat strip or strap of material used to encircle the waist," from Proto-Germanic *baltjaz (source also of Old High German balz, Old Norse balti, Swedish bälte), an early Germanic borrowing from Latin balteus "girdle, sword belt," which is said by Varro to be an Etruscan word.

The transferred sense of "broad stripe encircling something with its ends joined" is from 1660s; that of "broad strip or tract" of any sort, without notion of encircling (as in Bible belt) is by 1808. As a mark of rank or distinction, mid-14c.; references to boxing championship belts date from 1812. The mechanical sense is from 1795.

Below the belt "unfair" (1889) is from pugilism. To get something under (one's) belt was originally literal, to get it into one's stomach (1839), figurative use of that us by 1931. To tighten (one's) belt "endure privation" is from 1887.