Proto-IE: *(a)rew-
Meaning: sun, moon
Hittite: arma- c. 'Mond, Monat', Lyk. arma-, erme-, erm̃me-, Lyd. armTa- 'des Arm(a)ś' (Tischler 62 without etymology)
Old Indian: ravi- m. `sun'
Armenian: arev `Sonne'
Russ. meaning: солнце
References: WP II 358 f