Material (usually a flammable liquid) used to initiate or increase the spread of a fire. 

"that which hastens," especially combustion, 1854, from Latin accelerantem (nominative accelerans), present participle of accelerare "to hasten, quicken" (see accelerate). As an ad [..]

flammable fuel (often liquid) used by some arsonists to increase size or intensity of fire. May also be accidentally introduced when HAZMAT

<computer hardware> Additional hardware to perform some function faster than is possible in software running on the normal CPU. Examples include graphics accelerators and floating-point accelerators. (01 Mar 1994)

1. Anything that increases rapidity of action or function. 2. In physiology, a nerve, muscle, or substance that quickens movement or response. 3. A catalytic agent used to hasten a chemical reaction. 4. In nuclear physics, a device that accelerates charged particles (e.g., protons) to high speed in order to produce nuclear reactions in a target, of [..]