internal combustion engine

Definitions

General Science

  • noun a type of engine used in motor vehicles, where the fuel is a mixture of petrol and air burnt in a closed chamber to give energy to the pistons

Cars & Driving

  • noun a type of engine in which the fuel is burned within the cylinders of the engine (as opposed to, e.g., the steam engine) and the gaseous combustion products serve as the thermodynamic fluid; the spent gases are released into the atmosphere; the term internal combustion engine covers all types of reciprocating and rotary engines, but is typically used with reference to four-stroke petrol and diesel engines.
http://www.dictionarycentral.com/definition/internal-combustion-engine.html