noun
: a chamber within which combustion occurs: as
a. : the space in some boiler furnaces where the gases from the fire become more thoroughly mixed with air and burned
b. : the clearance space in the cylinder of an internal-combustion engine where the charge is compressed and ignited
c. : the part of a jet engine or gas turbine in which the propulsive power is developed by combustion of the injected fuel and the expansive force of the resulting gases