The meaning of “λυτρόω”

“But we trusted that it had been he which should have redeemed Israel: and beside all this, to day is the third day since these things were done.”

“Who gave himself for us, that he might redeem us from all iniquity, and purify unto himself a peculiar people, zealous of good works.”

“Forasmuch as ye know that ye were not redeemed with corruptible things, as silver and gold, from your vain conversation received by tradition from your fathers;”