noun

• Something that boosts.
• The first stage of a multistage rocket that provides the thrust for liftoff and the initial flight
• A motor-generator set used for voltage regulation in direct current electrical power circuits.
• Someone who is a fan or supporter of something.
• Someone who promotes a town or business
• A member of a booster club.
• A booster dose.
• A term that serves to amplify or strengthen an utterance, such as "really".
• A power-up item.
• A package of cards or figurines designed to add to a player's collection.
• A thief.