par·lay 
(pärlā′, -lē)
(pärlā′, -lē)tr.v. par·layed, par·lay·ing, par·lays
1. To bet (an original wager and its winnings) on a subsequent event.
2. To use to great advantage or transform into something better: parlayed some small investments into a large fortune.
n.
A bet comprising the sum of a prior wager plus its winnings or a series of bets made in such a manner.
[Alteration of paroli, staking of double the sum staked before in faro, from French, from obsolete Italian, probably from Italian parare, to place a bet, from Latin parāre, to prepare; see PARE.]