General:
* Energy: This is the most common and direct noun, referring to the force that makes things work or move.
* Stimulation: This emphasizes the process of making something more active or excited.
* Boost: This suggests a sudden increase in energy or activity.
Specific:
* Energizer: This refers to something that provides energy, like a battery or a drink.
* Energizing: This is the gerund form of the verb, acting as a noun. It's a bit more abstract than "energy" but still conveys the concept of energizing something.
Figurative:
* Spark: This emphasizes the sudden beginning of energy.
* Kickstart: This implies the action of starting something with energy.
Ultimately, the best noun to use depends on the specific situation and the desired effect.