Also found in: Dictionary, Thesaurus, Medical, Encyclopedia.
1. Literally, of a liquid, to boil so vigorously that it flows out of its container. If you put too much water in the pot, it might boil over.
2. To become extremely intense or out of control, especially after a period or escalation. Usually said of emotions. Things had been tense between my aunts for months, and those feelings finally boiled over in a yelling match on our family vacation. This protest is in danger of reaching a point where it boils over into a violent confrontation.
[for a liquid] to overflow while being boiled. (See also boil over (with something).) The sauce boiled over and dripped onto the stove. Don't let the stew boil over!
boil over (with something)
Fig. [for someone] to erupt in great anger. The boss boiled over with anger. Things got out of hand and the crowd's passions boiled over.
to become uncontrollable Anger boiled over when the police ordered the protesters to leave.
Etymology: based on the idea of liquid in a pan being heated until it boils over the side of the pot
Erupt in anger, excitement, or other strong emotion. For example, The mere mention of a tax increase will make Kevin boil over. This phrase alludes to overflowing while boiling. [Second half of 1800s]
1. To rise and flow over the sides of a container while boiling. Used of a liquid: I turned up the heat too high and the soup boiled over.
2. To erupt in violent anger: When I realized I had been robbed, I boiled over and started yelling.