General:
* Playtime: The time for playing.
* Gameplay: The process of playing a game.
* Role-play: Acting out a role or situation.
* Playoff: A series of games to decide a champion.
* Plaything: An object used for play.
* Playwright: A person who writes plays.
* Backstage: The area behind the stage in a theater.
* Underplay: To act in a restrained way.
* Overplay: To exaggerate a role or part.
More Specific:
* Basketball-play: A move or strategy in basketball.
* Football-play: A planned move in football.
* Hockey-play: A move or strategy in hockey.
* Card-play: The act of playing cards.
* Word-play: The clever use of words, often for humorous effect.
Let me know if you'd like more examples!