ἔσεσθαι

From LSJ

καὶ τῇ ὧν λέγεις καὶ φθέγγῃ ἡρωικῇ ἀληθείᾳ ἀρκούμενος, εὐζωήσεις → and satisfied with heroic truth in every word and sound which you utter, you will live happy

Source

French (Bailly abrégé)

inf. fut. de εἰμί.