Cool customer informal slang
Used to refer a person who stays calm or remains unruffled when facing difficulty
He is really a cool customer because during two hours of the competition, he remained unruffled.
It is necessary for a team leader to have the quality of a cool customer. It will help him make important decisions sensibly.
Used to advise somebody to calm down
Used to describe someone kind, calm and pleasant
1. To act or behave in an unrestrained, wild manner
2. To go away from a particular place or area
3. To separate from someone or something
To stay calm in a difficult situation and react to unexpected things quickly