accelerator

英[ək'seləreɪtə] 美[ək'sɛlə'retɚ]

1. a pedal that controls the throttle valve;

"he stepped on the gas"

2. a valve that regulates the supply of fuel to the engine

3. (chemistry) a substance that initiates or accelerates a chemical reaction without itself being affected

4. a scientific instrument that increases the kinetic energy of charged particles