Lose your head Definition 1 of 2Pro Tip 1/3Pressure Trigger This phrase often indicates someone couldn't cope with a stressful situation. During the debate, she lost her head and forgot all her points. Pro Tip 2/3Stay Calm It's used to advise someone to remain calm and not to overreact in a difficult situation. The key to solving this problem is to not lose your head. Pro Tip 3/3Emergency Reactions Commonly used to describe inappropriate or unhelpful behavior during emergencies. It's important not to lose your head during a crisis.