aisus represents the Gaulish divine name Aisus, recorded as Aisu-, Esu-, Esus, Aesu-, Aesus, Haesus, Hesus in inscriptions and in Latin manuscripts.16 The form in the present text is a masculine u-stem and stands in the vocative case; the vocative of u-stems was identical with the nominative. It is a widespread stem in religious terms and is attested in the languages of ancient Italy, e.g. Umbr. esono- 'divinus, sacer', esunu (neuter) 'sacrificium', Oscan Marruc. aisos (nom. pl.) 'dii', Paelig. aisis (dat. pl.) 'diis', Messap. aisa, which perhaps are loanwords from Etruscan, cf. Etr. aesar 'deus', aisuna 'divine'.17 Venetic aisu- 'god' also belongs here.l8 Further, there is an interesting correspondence of these words in Old Norse, eir, f., which occurs as the name of a goddess of medicine,19 and derives from *aisa via *aizō.