Flip your lid Definition 1 of 2Pro Tip 1/3Anger Outburst Use when describing someone losing control of their anger very quickly. When Joe missed the flight, he flipped his lid in the middle of the airport. Pro Tip 2/3Informal Expression Best used in casual conversation or writing, not in formal situations. My mom's going to flip her lid when she sees the broken vase. Pro Tip 3/3Emotional Intensity Conveys a high level of emotional reaction, stronger than just being upset or annoyed. He flipped his lid after seeing his car got towed.