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flip (one's) lid
1. To react to something, good or bad, with strong emotion. I had to talk to Mr. Myers about the botched report today, and boy, did he flip his lid. I knew Aunt June would be excited to hear I'm getting married, but she totally flipped her lid!
2. To go insane. Used humorously. Everyone thought I'd flipped my lid when I quit my lucrative marketing job and moved to India.
flip (one's) lidSlang
1. To react strongly, as with anger or enthusiasm.
2. To go crazy.