accelerator

noun

1.
a pedal that controls the throttle valve
accelerator pedal gas gas pedal gun throttle
Derived from:
accelerate
2.
a valve that regulates the supply of fuel to the engine
throttle throttle valve
Derived from:
accelerate
3.
(chemistry) a substance that initiates or accelerates a chemical reaction without itself being affected
catalyst
4.
a scientific instrument that increases the kinetic energy of charged particles
atom smasher particle accelerator