νεανιεύομαι
From LSJ
English (LSJ)
(Act. only in Hsch.), fut.
A -εύσομαι D.19.242: aor. ἐνεανιευσάμην Id.21.69:—Pass. (v. infr.):—to be a youth, Ph.1.303, Poll. 2.20. II more freq., act like a hot-headed youth, wilfully or wantonly, swagger, Ar.Fr.827, Lys Fr.324 S.; ν. εἰς τοὺς πολίτας behave so towards... Isoc.20.17, cf. Hyp.Eux.27; ἐν τοῖς λόγοις Pl.Grg. 482c; νεανιευσάμενος εἰπεῖν with youthful insolence, Plu.Cic.1:— Pass., ἐφ' ἅπασι τοῖς ἑαυτῷ νενεανιευμένοις to all his wanton acts, D. 21.18; τὰ ἐν τῇ βουλῇ νεανιευθέντα Plu.Mar.29. 2 make youthful, i.e. bold, promises, c. Adj. neut., ν. τοιοῦτον, ὡς . . D.19.194; οὐδ' ἐνεανιεύσατο τοιοῦτον οὐδέν Id.21.69; μέχρι τοῦ λόγου ν. Luc.Bis Acc. 21: c. inf., undertake with youthful spirit, Plu.Dem.3.