strap-hanger n.

1610s, "band of leather," from Scottish and/or nautical variant of strope "loop or strap on a harness" (mid-14c.), probably from Old French estrop "strap," from Latin stroppus "strap, band," perhaps via Etruscan, ultimately from Greek strophos "twisted band; a cord, rope," from strephein "to turn" (from PIE root *streb(h)- "to wind, turn"). Old English stropp, Dutch strop "halter" also are borrowed from Latin, and the Old English word might be the source of the modern one. Slang meaning "credit" is from 1828.

early 15c., "one who hangs (something)," especially "executioner," later also "one who chooses pictures for an exhibition;" agent noun from hang (v.). Meaning "something that is suspended" is late 15c. Meaning "thing from which something is hung" is from 1690s. Meaning "loop or strap in a garment for hanging on a peg" is from 1680s; of wood or wire coat or dress hangers from 1873. Hanger-on is from 1540s.