definition of
accelerator

[1] #1 accelerator n. [accelerator pedal, gas pedal, gas, throttle, gun] a pedal that controls the throttle valve; "he stepped on the gas". wn

[2] #2 accelerator n. [throttle, throttle valve] a valve that regulates the supply of fuel to the engine. wn

[3] #3 accelerator n. [catalyst] (chemistry) a substance that initiates or accelerates a chemical reaction without itself being affected. wn

[4] #4 accelerator n. [particle accelerator, atom smasher] a scientific instrument that increases the kinetic energy of charged particles. wn