boiling point 
noun
1The temperature at which a liquid boils and turns to vapour: pour in the water (not at boiling point but just below) [in singular]: a liquid with a high boiling point...
- Cato Maximilian Guldberg had already predicted, on theoretical grounds, that the freezing points, boiling points, and vapour pressures of solutions should all change at the same rate with increasing concentration.
- Evaporation is the change from liquid to vapor phase at a temperature below the boiling point of the liquid.
- The flask is then heated to a temperature above the boiling point of the liquid.
1.1The point at which anger or excitement breaks out into violent expression: emotions had reached boiling point and could spill over into violence racial tension surged to boiling point...
- Deliberately leading a herd to a neighbor's land was outrageous, and talking about it brought his anger to the boiling point.
- His anger was reaching the boiling point, his new-found control quickly vanishing.
- I was about to see Acorn Antiques the musical and had gone with my friend Mouse who is the only person I know whose excitement levels can reach boiling point.