Definitions for "Internal Combustion"
Pertains to any engine in which the heat or pressure necessary to produce power is developed in the engine cylinder by the combustion of a fuel.
the combustion of fuel inside a cylinder (as in an internal-combustion engine)
Burns inside. A type of engine that creates power by burning a fuel internally. Unlike externally as with a steam engine. Most cars on the road today use internal combustion engines, including those using petrol and diesel fuels.