εὐτυχές

From LSJ

ὅπλον μέγιστόν ἐστιν ἡ ἀρετή βροτοῖς → man's greatest weapon is virtue, virtue is the greatest weapon for mortals

Source

Russian (Dvoretsky)

εὐτῠχές: τό Thuc. = εὐτυχία.