εὐγονία
From LSJ
Τὸ νικᾶν αὐτὸν αὑτὸν πασῶν νικῶν πρώτη τε καὶ ἀρίστη. Τὸ δὲ ἡττᾶσθαι αὐτὸν ὑφ' ἑαυτοῦ πάντων αἴσχιστόν τε ἅμα καὶ κάκιστον. → Τo conquer yourself is the first and best victory of all, while to be conquered by yourself is of all the most shameful as well as evil
English (LSJ)
ἡ,
A fruitfulness, Pl.R.546a, X.Lac.1.6, Ph.2.390, etc.; opp. ἀγονία, Iamb. Comm. Math.15.
German (Pape)
[Seite 1060] ὴ, Fruchtbarkeit, Erzeugung guter oder schöner Kinder, Plat. Rep. VIII, 546 a; Xen. Lac. 1, 6; θρεμμάτων Plut. Rom. 24.