Glistering, exceeding white (stilbonta leuka lian). Old words, all of them. Matthew 17:2 has white as the light (leuka w to pw), Luke 9:29 "white and dazzling" (leuko exastraptwn) like lightning. So as no fuller on earth can whiten them (oia gnapeu epi th gh ou dunatai outw leukanai). Gnapw is an old word to card wool. Note outw, so, so white. Some manuscripts in Matthew add w ciwn, as snow. Probably the snow-capped summit of Hermon was visible on this very night. See on "Mt 17:2" for "transfigured."