1-3. repurchase. Redeem, ransom both mean to buy back. Redeem is wider in its application than ransom, and means to buy back, regain possession of, or exchange for money, goods, etc.: to redeem one's property. To ransom is to redeem a person from captivity by paying a stipulated price, or to redeem from sin by sacrifice: to ransom a kidnapped child. 8, 9. free, liberate, rescue, save.