κενότης
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)
ητος, ἡ,
A emptiness, Pl.R.585b, Ti.58b, Thphr.Sens.54; vanity, Phld.D.1.17; εἰς κενότητας ἄν μοι ὁ λόγος ἐξέπιπτε D.H.Is.20; κ. σφυγμοῦ Agathin. ap. Gal.8.936; cf. κενεότης.