1 US : a series of games that is played after the end of the regular season in order to decide which player or team is the champion — usually plural
The teams will once again face each other in the play-offs.
2 : a game or series of games that is played to decide the winner when people or teams are tied
We tied the first day, but I beat her the next day in a play-off.
an 18-hole play-off