Proto-Sino-Tibetan: *lăkʷ
Meaning: shine, flash
Tibetan: glog lightning.
Burmese: lak, prak to flash, gleam, glitter.
Comments: Gong 47. Cf. also Idu *lio, Mikir kelok 'white'. Cf. Austric: PAA *lɔ:k / *luok 'grey, white', PAN *bilak 'shine, glitter'.