κουρεύομαι
From LSJ
τὸ γὰρ εὖ πράττειν παρὰ τὴν ἀξίαν ἀφορμὴ τοῦ κακῶς φρονεῖν τοῖς ἀνοήτοις γίγνεται → undeserved success engenders folly in unbalanced minds
English (LSJ)
(κουρά) A take the tonsure, i.e. enter a monastery, of a nun, Just.Nov.134.10.1; have the hair cut, of four-year-old children, Sch.Nic.Al.417.