Definitions
1.nounOne who, or that which, activates.
2.nounSomething that activates a catalyst
3.nounAny chemical or agent which regulates one or more genes by increasing the rate of transcription.
4.nounA type of effector that increases the rate of enzyme-mediated reactions.
5.nounA type of dopant used in phosphors and scintillators.
6.nounAn agent that enables the flotation of a mineral or minerals.