Suzanne Raymer has suggested a post on parley versus parlay.
Both words may be used as either noun or verb.
As a noun, parley can mean “speech” or “conversation.” Its most common use is to mean speech between opposing sides, a conference with an enemy to discuss terms. As a verb it means “to discuss terms,” or “hold discussion with.”
Parlay is a betting term. As a noun, it means “a cumulative series of bets.” The winnings of subsequent bets are bet again. As the bettor continues to win, the gains continue to increase. As a verb, parlay means “to use the winnings from a previous bet to make another bet.”
Parley [pär’lē] is from French parler, “to speak.”
Parlay [pär’lā’] comes from French parole which comes from Italian parole, “words, promises.” Parlay entered English in 1701 as a term in the card game faro. The gambling term took on the meaning “to exploit to advantage” in 1942.
Uses of parlay:
David Lusterman parlayed a $10000 investment into a company with $1.2 million in revenues
Witness Bill Blount parlayed political skills into a mega-dollar business
She parlayed a $350 investment into a multi-million dollar business…
Uses of parley:
Governors seek fresh parley with teachers
German politicians plan June parley with Hamas minister
For the moment they are parleying with the king’s brother-in-law