, from Proto-Germanic *raskaz, *raskuz, *raþskaz, *raþskuz, from Proto-Indo-European *ret-. Cognate with Dutch rasch, ras, Middle Low German rasch, German rasch, Swedish rask, Icelandic röskur.
Likely from Old French rasche ("rash, scurf"), from Vulgar Latin root *rāsicāre, from Latin rāsus ("scraped, scratched"), from Latin rādō. More at raze/rase.
Compare French ras ("short-nap cloth"), Italian and Spanish raso, satin, or Italian rascia ("serge"), German Rasch, probably from Arras in France.