φρονηματίζομαι
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)
Pass.,
A to become presumptuous, Arist.Pol.1274a13; φρονηματισθέντες ἐκ τῶν ἔργων ib.1341a30; πεφρονηματισμένοι διά τι ib.1284b2, cf. D.S.5.24; ἐπὶ τοῖς γεγονόσι Plb.21.25.8, D.S.9.2; c. dat., νίκῃ Id.12.48; πλῆθος τῶν -ισμένων ὡς ὁμοίων κατ' ἀρετήν Arist.Pol.1306b28; φ. ὅτι . . to get a notion that... Sch.Theoc.14.48.