The Collaborative International Dictionary of English v.0.48:
Exhaust \Ex*haust"\, a. [L. exhaustus, p. p.]
1. Drained; exhausted; having expended or lost its energy.
2. Pertaining to steam, air, gas, etc., that is released from
the cylinder of an engine after having preformed its work.
Exhaust draught, a forced draught produced by drawing air
through a place, as through a furnace, instead of blowing
Exhaust fan, a fan blower so arranged as to produce an
exhaust draught, or to draw air or gas out of a place, as
out of a room in ventilating it.
Exhaust nozzle, Exhaust orifice (Steam Engine), the blast
orifice or nozzle.
Exhaust pipe (Steam Engine), the pipe that conveys exhaust
steam from the cylinder to the atmosphere or to the
Exhaust port (Steam Engine), the opening, in the cylinder
or valve, by which the exhaust steam escapes.
Exhaust purifier (Milling), a machine for sorting grains,
or purifying middlings by an exhaust draught. --Knight.
Exhaust steam (Steam Engine), steam which is allowed to
escape from the cylinder after having been employed to
produce motion of the piston.
Exhaust valve (Steam Engine), a valve that lets exhaust
steam escape out of a cylinder.