flip one's lid

[flip one's lid] also [flip one's wig] {slang} 1. To lose one'stemper.

When that pushy salesman came back Mom really flipped herlid.

Compare: BLOW A FUSE. 2. To lose your mind; become insane.

When he offered me three times the pay I was getting, I thought hehad flipped his lid.

3. To become unreasonably enthusiastic.

Sheflipped her lid over a hat she saw in the store window.

He'sflipped his lid over that new actress.