1. 沸溢；潽出
When a liquid that is being heated boils over, it rises and flows over the edge of the container.

2. （感情）爆发；失去理智；大怒
When someone's feelings boil over, they lose their temper or become violent.

1. overflow or cause to overflow while boiling

e.g. The milk is boiling over

Synonym: overboil