Parlay means to bet one’s winnings over again. It can also mean to exploit something into something more valuable.
- He parlayed his blackjack winnings into enough money to pay for all his expenses.
- Using an infomercial, he parlayed a simple invention into a national bestseller.
Parley, as a verb, means to confer with an enemy, to negotiate, or to discuss.
- The leaders plan to parley their differences in a neutral location.
Parley, as a noun, refers to a conference to resolve disagreements or disputes.
- The two leaders agreed to meet for a parley.