shash

Etymology 1

See sash.

noun

1. (obsolete) The scarf of a turban.
2. (obsolete) A sash.

Etymology 2

Imitative?

noun

1. (television) Synonym of snow (“random pattern of dots when there is no signal”)
   Even productions designed for office or home video viewing usually need a title sequence to mark off the empty tape, hiss and shash from the prepared recording […] 1997, Paul Kriwaczek, Documentary for the Small Screen
   No one sees shash now, but it was naked television. Shash was the term for those black-and-burst patterns that danced across the screen when there was nothing being broadcast. 2012, Paul Farley, Michael Symmons Roberts, Edgelands: Journeys Into England's True Wilderness, page 159

verb

1. (intransitive, rare) To produce white noise.
   The machine shashed and crackled, broadcasting silence. Urgently the man repeated, 'Shearwater, Shearwater, Shearwater. This is Brewmarine. Keith speaking. Over. Over.' More shashing, more silence. 2003, Libby Purves, Casting Off