The idiom "keep one's hair on" means to remain calm or composed even in a stressful or frustrating situation. Its antonyms, or words with opposite meanings, are phrases like "lose one's cool," "freak out," "be on edge," or "panic." These expressions suggest a lack of composure or control, and convey a sense of anxiety, fear or agitation. Other antonyms for "keep one's hair on" include behaving impulsively, lashing out in anger, or succumbing to frustration. To avoid these negative outcomes, it is important to maintain a balanced, measured approach to challenges and crises, and cultivate strategies to remain calm and focused.
