Comment: 4th class in Rut. and Arch. Cf. also Ag. Bursh. ʡakʷ, Fit. eḱʷ, Burk., Tp. ʡäkʷ 'light', Arch. ak:u-kes 'to dawn' ( = Tab. aku xuz id.). External data show that the original form *ʡakʷan (retained in Arch., possibly also in Ud., where kaj may reflect *(ʡa)kʷan with phonetic loss of -n) was reinterpreted in most Lezghian languages as the oblique base from *ʡakʷa (cf., e.g., the Lezg. paradigm: ekʷ, erg. eküni).
See Бокарев 1961, 63; Лексика 1971, 199; Гигинейшвили 1977, 80.