γrr - to be white and to shine by its whiteness (face)
(Lane 2237)
Also γurrat- ‘star, white spot on a horse's forehead; everything that shines’ (Lane 2238), ˀaγarr- ‘white and which shines by its whiteness’ (Lane 2240).
PWS
*γrr - to be white on black or black on white
(Kogan 2005c:191)