Proto-IE: *ata, *atta <PIH *a->
Meaning: father
Hittite: atta- c., Lyd. ata- (Tischler 92)
Other Iranian: Osset äda `Vater'
Old Greek: voc. átta `Väterchen'
Latin: atta m. `Vater; Kosewort der Kinder dem Vater gegenüber'
Celtic: MIr aite `Pflegevater'
Albanian: at `Vater'
Russ. meaning: отец
References: WP I 44, Buck 103