Activator (noun)

A substance or device that is used to activate or bring something into operation.

Origin:

Derived from the verb "activate", which means to make something active or bring it into operation.

Examples:

1. The activator in the car's ignition system is responsible for starting the engine.
2. Chemicals activator is added to the mixture to initiate the reaction.
3. A specific enzyme activator is required to catalyze the metabolic process.
4. The UV light activator is used to cure dental fillings.
5. The activator in the fire alarm system triggers the alarm when it detects smoke.