κουρεύομαι
From LSJ
φιλοσοφίαν καινὴν γὰρ οὗτος φιλοσοφεῖ → this man adopts a new philosophy
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.