Accelerator - Definition

n 1: a pedal that controls the throttle valve; "he stepped on
the gas" [syn: accelerator, accelerator pedal, gas
pedal, gas, throttle, gun]
2: a valve that regulates the supply of fuel to the engine [syn:
accelerator, throttle, throttle valve]
3: (chemistry) a substance that initiates or accelerates a
chemical reaction without itself being affected [syn:
catalyst, accelerator] [ant: anticatalyst]
4: a scientific instrument that increases the kinetic energy of
charged particles [syn: accelerator, particle
accelerator, atom smasher]