razor: [13] A razor is etymologically a ‘scraper’. The word was borrowed from Old French rasor, a derivative of raser ‘scrape, shave’ (from which English gets raze [16]). This in turn went back via Vulgar Latin *rasāre to Latin rādere ‘scrape’, source also of English abrade [17], erase, and possibly rascal. => abrade, erase, rascal
late 13c., from Old French raseor "a razor" (12c.), from raser "to scrape, shave" (see rase). Razor clam (1835, American English) so called because its shell resembles an old folding straight-razor. Razor-edge figurative of sharpness or a fine surface from 1680s.
