Flammable

adj. combustible, capable of being easily ignited

Inflammability is the ease with which a substance will ignite, causing fire or combustion. Materials that will ignite at temperatures commonly encountered are considered inflammable, with various specific definitions giving a temperature requirement. The flash point is the important characteristic. A volatile substance may have sufficient vapor pressure to form flammable (or even explosive) mixtures with air in temperatures as low as , so that ignition can occur even without direct contact. Flash points below are regulated in the United States by OSHA as potential workplace hazards. Examples of flammable liquids are gasoline, ethanol, and acetone. Diesel fuel is in one of the less heavily regulated flammability categories, and biodiesel is considered nonflammable or noninflammable with a flash point usually over even though biodiesel will combust inside a diesel engine.
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Adjective
1. possible to burn
(synonym) burnable, ignitable, ignitible, inflammable
(similar) combustible

With respect to a fluid or gas, means susceptible to igniting readily or to exploding. (14CFR1)

Any material that ignites easily and will burn rapidly.