A.confirm, establish, make good, “τοῖς δικασταῖς τὴν δόξαν” Pl.Cri.53b; “δωρεὰν” Is.1.18; “εἴτε δεξιὰς δοῖεν ἐβεβαίουν” X.Cyr.8.8.2, etc.; ἔργῳ βεβαιούμενα, opp. ἀκοῇ λεγόμενα, Th.1.23; β. λόγον make good one's word, Lys.20.32; “β. τὴν πρᾶξιν” X.An.7.6.17; treat as valid, “τὰς αὑτῶν αἰσθήσεις” Metrod.1, cf. Epicur.Sent.24; β. τινί τι secure one the possession of a thing, οὐδ᾽ ἡμῖν αὐτοῖς βεβαιοῦμεν [τὴν ἐλευθερίαν] Th.1.122; “τοῖς θεοῖς βεβαιοῦντες τοὺς νόμους οὒς ἐψηφίσασθε” Lys.6.29, cf. D.21.30; “τὴν ἀρχήν τινι” Plu.Sull.22; “τὸν λόγον” Ev.Marc.16.20:—Med., establish for oneself, secure, “σφᾶς αὐτούς” Th. 1.33; τὴν ἀρχήν, τὴν φιλίαν τινός, Id.6.10,78; β. τινάς confirm them in one's interest, ib.34; “βασιλείαν” Paus.3.11.4; “τὰ περὶ τῆς βοηθείας” Plb.2.51.5.
2. Med., secure one's ground in argument, Pl.Tht. 169e; confirm oneself in an opinion, Id.Grg.489a, Prt.348d.
3. guarantee the validity of a purchase, warrant the purchaser's title, “β. τινὶ τὸ βαλανεῖον” Is.5.23, cf. Din.1.42, D.37.12, SIG46.4 (Halic., v B. C.); “τὴν μίσθωσιν” BGU1119.47 (i B. C.): generally, “β. τοὺς κανόνας” Arr.Epict.2.11.24.
II. intr., determine, show itself positively, τοῖσιν ἐνδοιαστῶς ἔχουσι . . ἐβεβαίωσε [ἡ νοῦσος] Hp.Epid.1.2.