Boiling point, the temperature at which a fluid is converted into vapor, with the phenomena of ebullition. This is different for different liquids, and for the same liquid under different pressures. For water, at the level of the sea, barometer 30 in., it is 212 ° Fahrenheit; for alcohol, 172.96° for ether, 94.8° for mercury, about 675°. The boiling point of water is lowered one degree Fahrenheit for about 550 feet of ascent above the level of the sea. -- Boiling spring, a spring which gives out very hot water, or water and steam, often ejecting it with much force; a geyser. -- To be at the boiling point, to be very angry. -- To keep the pot boiling, to keep going on actively, as in certain games. [Colloq.]