grown-up 
(grōnŭp′)
(grōnŭp′)adj.
1. Of, characteristic of, or intended for adults: a grown-up discussion.
2. Having or showing maturity in outlook, attitude, or appearance: a grown-up attitude toward work.
- play (one's) cards
- play one's cards
- play on (or upon)
- play out
- playpen
- play possum
- playroom
- playsuit
- play the devil with
- play the field
- play the fool
- play the game
- play therapist
- play therapy
- plaything
- play up
- play upon
- play up to
- playwear
- play with
- play with a full deck
- play with fire
- play with (oneself)
- play with oneself
- playwright