a person or thing that supports, assists, or increases power or effectiveness - Also called: launch vehicle
the first stage of a multistage rocket a radio-frequency amplifier connected between an aerial and a receiver to amplify weak incoming signals a radio-frequency amplifier that amplifies incoming signals, retransmitting them at higher power - another name for supercharger
- short for booster dose
WordReference Random House Learner's Dictionary of American English © 2026
boost•er /ˈbustɚ/USA pronunciation
n. [countable]
WordReference Random House Unabridged Dictionary of American English © 2026- a person or thing that boosts, esp. an energetic supporter:The president's biggest booster was the senator from his home state.
- Rocketrythe first stage of a rocket and the principal source of thrust.
- MedicineAlso called ˈboost•er ˌshot. a dose of a medicine given to maintain a previous one:a booster shot for tetanus.
boost•er
(bo̅o̅′stər),USA pronunciation n.
boost′er•ish, adj.
- a person or thing that boosts, esp. an energetic and enthusiastic supporter.
- Electricitya device connected in series with a current for increasing or decreasing the nominal circuit voltage.
- Rail Transportany machine, device, phenomenon, etc., that helps to move a train, as a tailwind, downgrade, roller bearings, or esp. a helper locomotive.
- Militaryan explosive more powerful than a primer, for ensuring the detonation of the main charge of a shell.
- [Rocketry.]
- Rocketrya rocket engine used as the principal source of thrust in the takeoff of a rocket or missile.
- Rocketrythe first stage containing this engine and its fuel supply, which may or may not be detached from the rocket when the fuel has been consumed.
- MedicineAlso called boost′er dose′, boost′er shot′. a dose of an immunizing substance given to maintain or renew the effect of a previous one.
- Drugs[Pharm.]a chemical compound, medicinal substance, or the like, that serves as a synergist.
- Radio and Televisiona radio-frequency amplifier for connecting between a radio or television antenna and the receiving set to intensify the received signal.
- Hydraulicsan auxiliary pump, used in a pipeline or other system, to add to or maintain a prevailing amount of pressure or vacuum.
- Slang Termsa shoplifter or petty thief.
- boost + -er1 1885–90, American.
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