Flash point

The lowest temperature at which it can vaporize to form an ignitable mixture in air
Reference: Chemical Process Safety – Fundamentals with Applications, 2nd Ed., Daniel A. Crowl/Joseph F. Louvar
Minimum temperature at which, under specified test conditions, a liquid gives off sufficient combustible gas or vapour to ignite momentarily on application of an effective ignition source.
Reference: S2S (safety to safety website: EN 1127-1: 1998, EN 1127-2:2002 (E), EN 13237:2003 (E))
Science/Flammability/Terms of Parameters in Combustion