It is Finished

Hi All,

I have been trying to figure this word out for a while with no success.

I have heard it many times in media, and it sounds something like けちゃこすけ, but I'm sure i'm spelling it wrong. It is used in sentences when saying to finish something (i.e. Let's put an end to this; It will be taken care of).

Anyone know what word this is?

Thanks!

けっちゃく（＝決着）をつける, perhaps?