ἐνεργάζεσθαι

From LSJ

φωνὰ τύ τίς ἐσσι καὶ οὐδὲν ἄλλο → it's all voice you are, and nothing else | it's all voice ye are, and nought else

Source

Greek > English (Woodhouse Verbs Reversed)

(see also ἐνεργάζομαι): engender, foster, produce in persons, produce in things