keep/lose your cool

keep (one's) cool

To maintain control of one's composure, temper, or nerve in a given situation. He really kept his cool when the waiter dropped his food. I tried to keep my cool during the interview, but I was extremely nervous the whole time.
See also: cool, keep

lose (one's) cool

To lose control of one's composure, temper, or nerve in a given situation. He really lost his cool when the waiter dropped his food. I really lost my cool during the interview.
See also: cool, lose
Farlex Dictionary of Idioms.

keep your cool

COMMON If you keep your cool, you control your temper and stay calm in a difficult situation. Hilde's one of those born managers — keeps her cool in a crisis. I knew I had to keep my cool, but it was hard.
See also: cool, keep

lose your cool

COMMON If you lose your cool, you suddenly get angry and behave in a bad-tempered or uncontrolled way. At this point, I lost my cool and shouted `for goodness sake, stop!' `Why don't you sit down and have a drink?' — `I don't want a drink,' Anne replied, losing her cool.
See also: cool, lose
Collins COBUILD Idioms Dictionary, 3rd ed.

lose your cool

lose control of your temper or emotions. informal
See also: cool, lose
Farlex Partner Idioms Dictionary

keep/lose your ˈcool

(informal) stay calm/get angry, excited, etc: He was very insulting. I really don’t know how I managed to keep my cool.
See also: cool, keep, lose
Farlex Partner Idioms Dictionary
See also:
  • keep (one's) cool
  • keep cool
  • keep one’s cool
  • keep one's cool
  • keep your cool
  • lose (one's) cool
  • lose cool
  • lose one’s cool
  • lose one's cool
  • lose your cool