Pronunciation: (ak-sel'u-rā"tur),[key] —n. 1. a person or thing that accelerates.
2. Auto.a device, usually operated by the foot, for controlling the speed of an engine.
3. Brit.any two- or three-wheeled motor vehicle, as a motorcycle or motor scooter.
4. Photog.a chemical, usually an alkali, added to a developer to increase the rate of development.
5. Also called accelerant.Chem.any substance that increases the speed of a chemical change, as one that increases the rate of vulcanization of rubber or that hastens the setting of concrete, mortar, plaster, or the like.
6. Anat.,Physiol.any muscle, nerve, or activating substance that quickens a movement.
7. Also called atom smasher, particle accelerator.Physics.an electrostatic or electromagnetic device, as a cyclotron, that produces high-energy particles and focuses them on a target.
8. Econ.See acceleration coefficient.