- (chemistry) A substance which speeds up chemical reactions.
- (physics) A device that accelerates charged subatomic particles.
- A device for causing acceleration.
- (photography) A chemical that reduces development time.
- (computing) accelerator key
- One who, or that which, accelerates.
- (vehicles) An accelerator pedal.
- (physiology, medicine) A muscle or nerve that speed the performance of an action.