The pedal in a vehicle that you press to increase speed (the gas pedal); commonly operated with the right foot and often shortened to "accelerator" or "gas."
車の運転では右足でアクセルペダルを踏みます。
When driving a car, you press the accelerator pedal with your right foot.
急にアクセルペダルを強く踏んだので車が加速した。
The car accelerated because I suddenly pressed the accelerator pedal hard.
故障でアクセルペダルが戻らなくなったため、整備工場に持っていった。
Because the accelerator pedal wouldn't return due to a malfunction, I took it to the repair shop.