boil over

verb4

1. •
   To boil to such an extent as to overflow its container.

   • I forgot about the rice and it boiled over.
2. •
   To reach the point where aggressive action is taken.
3. •
   To act aggressively angry.

   • He boiled over all night.
4. •
   To buck aggressively.

   • The stallion boiled over, throwing Robert from her back.