booster
//ˈbuːstər//
Noun
boosterSingular
boostersPlural
1
A device or substance that increases the power, effectiveness, or speed of something.
The signal booster improved the Wi-Fi connection throughout the house.
2
An additional dose of a vaccine given to maintain or strengthen immunity.
I received a booster shot to maintain my immunity against the flu.
3
A rocket or engine that provides additional thrust, especially during the initial stage of a launch.
The rocket's booster separated successfully after launch.
4
A person or thing that supports, promotes, or encourages something or someone.
She has always been a booster of local businesses.