activator

noun

1. One who, or that which, activates.
2. (physical)Something that activates a catalyst
3. Any chemical or agent which regulates one or more genes by increasing the rate of transcription.
4. A type of effector that increases the rate of enzyme-mediated reactions.
5. A type of dopant used in phosphors and scintillators.
6. An agent that enables the flotation of a mineral or minerals.
7. A hand-held device that delivers a controlled fast thrust to a joint, muscle, etc., to help stimulate nervous system activity.