1. Physics, Chem.the temperature at which the vapor pressure of a liquid is equal to the pressure of the atmosphere on the liquid, equal to 212°F (100°C) for water at sea level. Abbr.: b.p.
2. the point beyond which one becomes angry, outraged, or agitated.
3. the point at which matters reach a crisis.
Random House Unabridged Dictionary, Copyright © 1997, by Random House, Inc., on Infoplease.