• Okay, that’s it. You can go now.

2—used to say that something is all that is needed or wanted 

• I came here just to visit the museum and that’s it.

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 one will not accept any more of something 

• That’s it! No more horseplay in the house!