ἐξυβρίζειν

From LSJ

μηδενί δίκην δικάσῃς πρίν ἀμφοῖν μῦθον ἀκούσῃς → do not give your judgement on anything until you have heard a speech on both sides

Source

Greek > English (Woodhouse Verbs Reversed)

(see also ἐξυβρίζω): act insolently, be audacious

Lexicon Thucydideum

insolescere, to become insolent, 1.84.2.
insolescere, to become insolent, 3.39.5.