[grah-twahr; French gra-twar]
noun, plural grat·toirs [grah-twahrz; French gra-twar] /grɑˈtwɑrz; French graˈtwar/. Archaeology.
  1. a flaked stone implement, usually Upper Paleolithic, retouched at the end and used probably for working wood or cleaning hides; scraper.

Origin of grattoir

1870–75; < French, equivalent to gratt(er) to grate2 + -oir -ory2 Unabridged Based on the Random House Unabridged Dictionary, © Random House, Inc. 2018