sash (n.1)

strip of cloth, 1590s, originally in reference to Oriental dress, "strip of cloth twisted into a turban," from Arabic shash "muslin cloth." Meaning "strip of cloth worn about the waist or over the shoulder" first recorded 1680s.

framed part of a window, 1680s, sashes, mangled Englishing of French châssis "frame" of a window or door (see chassis). French word taken as a plural and -s trimmed off by 1704. Sash-weight attested from 1737.