ᾖσμαι

From LSJ

οὕτως εἴη ἡμίν ὁ Θεός βοηθός καὶ τὸ ἱερὸν Αὐτοῦ Εὐαγγέλιον ὧδε ἐμφανισθέντα-ὁρκισθέντα → so help us God and Ηis holy Gospel the things here declared and sworn

Source

French (Bailly abrégé)

pf. Pass. de ᾄδω.

Russian (Dvoretsky)

ᾖσμαι: pf. pass. к ᾄδω.