τερπνῶς

From LSJ

αὐτάρκης ἔσῃ, ἂν μάθῃς τί τὸ καλὸν κἀγαθόν ἐστι → you will be contented with your lot if you learn what the honourable and good is

Source

Russian (Dvoretsky)

τερπνῶς: радостно, в наслаждениях (τρέφειν τινά Soph.).