I. noun
1. also flashing point : the lowest temperature at which the vapors above a volatile combustible substance (as a petroleum product) ignite momentarily in air when tested usually by applying a small flame under specified conditions
the degree of flammability of a liquid is expressed mainly by means of its flash point — Dict. of Fire Technology
2. : a point (as of interest or tension) at which someone or something bursts suddenly into action or being
near the flash point of war
II. noun
: tinderbox 2