to relax or calm down The best thing both sides can do is to cool it and then get back to talking about the problem.Hugh stepped between the two boys and told them to cool it.
Usage notes: often used as an order: Nikki, leave your brother alone, and, Josh, cool it!
1. Calm down, relax, as in John was beginning to seethe, but I told him to cool it. [Slang; c. 1950]
2. Stop what one is doing, especially stop talking or behaving conspicuously, as in We'd be wise to cool it until the scandal blows over. It is also used as an imperative, as in Cool it! We'll be in trouble if anyone hears you. [Slang; c. 1950]