for keeps

[for keeps] {adv. phr.} 1. For the winner to keep.

They playedmarbles for keeps.

2. {informal} For always; forever,

He left townfor keeps.

Syn.: FOR GOOD. 3. Seriously, not just for fun.

This isnot a joke, it's for keeps.

- Often used in the phrase "play forkeeps".

The policeman knew that the robber was trying to shoot him.He was playing for keeps.