that is it (or that's it)
informal
1
— used to say that something is finished or completed
Okay, that's it. You can go now.
2
— used to say that something is all that is needed or wanted
I came here to visit the museum and that's it. [=that is all I wanted to do here]
3
— used to say that something is correct
“I can't remember his name.” “I think it was Brian Johnson.” “Yes, that's it.”
4
— used in an angry or annoyed way to say that you will not accept any more of something
That's it! I'm leaving!
• • •
Main Entry: ↑it
Useful english dictionary. 2012.