cool off

verb

1. To decrease in temperature, activity, or temper.

   “You are getting a little too angry; you need to cool off.”

   “The metal will take about three hours to cool off after the molding.”

2. To cause to decrease in temperature, activity or temper.

   “At first he was very angry, but his friends managed to cool him off.”

3. To lose interest or enthusiasm [with on].

   “While talking about freight, I must express my regret that the Government seem to be cooling off on the Channel Tunnel.”

   “The YouGov research – contrary to other polls – also suggested Brits have cooled off on the idea of Thatcher's flagship "right to buy" policy”

4. To be imprisoned.

   “He's cooling off in the state pen.”

5. To kill (someone).
6. To wait for a furor to die down; to hide during a police manhunt.

   “After doing the job, he went to the safehouse to cool off.”