ἐξαγοράζω

: 1 aorist ἐξηγόρασα; (present middle ἐξαγοράζομαι);
1. to redeem i. e. by payment of a price to recover from the power of another, to ransom, buy off (cf. ἐκ, VI. 2): properly, θεραπαινιδα, Diodorus 36, 1, p. 530; metaphorically, of Christ freeing men from the dominion of the Mosaic law at the price of his vicarious death (see ἀγοράζω, 2 b.), τινα, Gal 4:5; with addition of ἐκ τῆς κατάρας τοῦ νόμου, Gal 3:13.
2. to buy up, Polybius 3, 42, 2; Plutarch, Crass. 2; middle τί, to buy up for oneself, for one's use (Winers Grammar, § 38, 2 b.; Buttmann, 192 (166f)): tropically, in the obscure phrase, ἐξαγοραζόμενοι τόν καιρόν, Eph 5:16 and Col 4:5, where the meaning seems to be to make a wise and sacred use of every opportunity for doing good, so that zeal and well-doing are as it were the purchase-money by which we make the time our own; (active ἐξαγοράζειν καιρόν, to seek (to gain time (A. V.) i. e.) delay, Dan 2:8; middle with the accusative of thing, 'by ransom to avert evil from oneself', 'to buy oneself off or deliver oneself from evil': διά μιᾶς ὥρας τήν αἰώνιον κόλασιν ἐξαγοραζόμενοι, of the martyrs, Martyr. Polycarp, 2, 3 [ET]).