activator

noun

1. 1

   One who, or that which, activates.

2. 2

   Something that activates a catalyst

3. 3

   Any chemical or agent which regulates one or more genes by increasing the rate of transcription.

4. 4

   A type of effector that increases the rate of enzyme-mediated reactions.

5. 5

   A type of dopant used in phosphors and scintillators.

6. 6

   An agent that enables the flotation of a mineral or minerals.