ἐκμανθάνω · ekmanthanō — LSJ
learn thoroughly, and, in past tenses, to have learnt thoroughly, know full well, ἐ. τὴν [Ἑλλάδα] γλῶσσαν Hdt. 2.154; ἀνδρὸς ψυχήν S. Ant. 175; ἐ. τι ἀπό τινος A. Pr. 256; ἔκ τινος Pl. Ax. 371a; παρά τινος S. OT 286; τοῦ θεοῦ τί πρακτέον ib. 1439, cf. OC 114, Ar. Ec. 244; ἐ. ὅτι.. Hdt. 3.134.
examine closely, search out, Id. 7.28, E. IT 667, X. Cyr. 1.6.40.
learn by heart, ὅλους ποιητάς Pl. Lg. 811a, cf. Aeschin. 3.135; ᾄσματα Thphr. Char. 27.7; Σαπφοῦς τἀρωτικά Epicr. 4; Διονυσίου δράματα Ephipp. 16; ἵνα πολλάκις ἀκούοντες τῶν ἐπῶν ἐκμανθάνωμεν τὴν ἔχθραν Isoc. 4.159.