verb transitive: 1. to use an initial asset to achieve something more valuable.
2. to gamble an initial stake and winnings on a subsequent bet, race, contest, etc.
noun: a bet that uses the earlier bet and its winnings as the new bet.
An alteration of paroli (staking the double of the sum staked before), from French, from Italian paroli, plural of paraolo, perhaps from paro (equal), from Latin par (equal). Earliest documented use: 1828
Usage (from Wordsmith)
“Pacquaio has also parlayed his enormous popularity at home into a political career.”
Victor Mather; A Boxer Who Can Sing, Dance, and Legislate; The New York Times; Apr 17, 2015.