'To boil over' definitions:

Definition of 'To boil over'

From: GCIDE

Boil \Boil\ (boil), v. i. [imp. & p. p. Boiled (boild); p. pr. & vb. n. Boiling.] [OE. boilen, OF. boilir, builir, F. bouillir, fr. L. bullire to be in a bubbling motion, from bulla bubble; akin to Gr. ?, Lith. bumbuls. Cf. Bull an edict, Budge, v., and Ebullition.]
1. To be agitated, or tumultuously moved, as a liquid by the generation and rising of bubbles of steam (or vapor), or of currents produced by heating it to the boiling point; to be in a state of ebullition; as, the water boils. [1913 Webster]
2. To be agitated like boiling water, by any other cause than heat; to bubble; to effervesce; as, the boiling waves. [1913 Webster]
He maketh the deep to boil like a pot. --Job xii. 31. [1913 Webster]
3. To pass from a liquid to an a["e]riform state or vapor when heated; as, the water boils away. [1913 Webster]
4. To be moved or excited with passion; to be hot or fervid; as, his blood boils with anger. [1913 Webster]
Then boiled my breast with flame and burning wrath. --Surrey. [1913 Webster]
5. To be in boiling water, as in cooking; as, the potatoes are boiling. [1913 Webster]
To boil away, to vaporize; to evaporate or be evaporated by the action of heat.
To boil over, to run over the top of a vessel, as liquid when thrown into violent agitation by heat or other cause of effervescence; to be excited with ardor or passion so as to lose self-control. [1913 Webster]