The Collaborative International Dictionary
Combustion chamber \Com*bus"tion cham`ber\ (Mech.)
A space over, or in front of, a boiler furnace where the gases from the fire become more thoroughly mixed and burnt.
The clearance space in the cylinder of an internal combustion engine where the charge is compressed and ignited.
Wiktionary
n. An enclosed space, within a heat engine, in which the fuel is mixed and reacted with air or other oxidizing agent in a controlled manner
Wikipedia
A combustion chamber is that part of an internal combustion engine (ICE) in which the fuel/air mix is burned.
Usage examples of "combustion chamber".
A schedule had to be worked out with the business office to permit as much use of the pile as possible to be diverted to making atomic fuel, and a giant combustion chamber for atomic fuel had to be designed and ordered to replace the pile itself during the interim between the time it was shut down on earth and the later time when sufficient local, smaller plants could be built to carry the commercial load.
Paul had not expressed any overt criticism of the work Andrew was doing, other than his initial response that Andrews new combustion chamber might be less efficient than the atomic cell that powered his body now.
Foyle brought ice from the frozen galley tanks, melted it with his own body heat, and added water to the jet combustion chamber.
In return for their own large annual retainer, Feingold and Martin involved themselves in the legal aspects of the new combustion chamber.