See more synonyms for booster on
  1. a person or thing that boosts, especially an energetic and enthusiastic supporter.
  2. Electricity. a device connected in series with a current for increasing or decreasing the nominal circuit voltage.
  3. Railroads. any machine, device, phenomenon, etc., that helps to move a train, as a tailwind, downgrade, roller bearings, or especially a helper locomotive.
  4. Military. an explosive more powerful than a primer, for ensuring the detonation of the main charge of a shell.
  5. Rocketry.
    1. a rocket engine used as the principal source of thrust in the takeoff of a rocket or missile.
    2. the 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.
  6. Medicine/Medical. Also called booster dose, booster shot. a dose of an immunizing substance given to maintain or renew the effect of a previous one.
  7. Pharmacology. a chemical compound, medicinal substance, or the like, that serves as a synergist.
  8. a radio-frequency amplifier for connecting between a radio or television antenna and the receiving set to intensify the received signal.
  9. an auxiliary pump, used in a pipeline or other system, to add to or maintain a prevailing amount of pressure or vacuum.
  10. Slang. a shoplifter or petty thief.

Origin of booster

An Americanism dating back to 1885–90; boost + -er1
Related formsboost·er·ish, adjective Unabridged Based on the Random House Unabridged Dictionary, © Random House, Inc. 2018

Related Words for booster

patron, enthusiast, promoter, backer, sponsor, rooter

Examples from the Web for booster

Contemporary Examples of booster

Historical Examples of booster

  • The primary—ah, booster, as you say, breaks free at twelve miles.

    The Big Tomorrow

    Paul Lohrman

  • Like the rest of you, I knew nothing of the true action of the booster.

    The Long Voyage

    Carl Richard Jacobi

  • They haven't got the booster or anything like it, or they'd have used it.

    Masters of Space

    Edward Elmer Smith

  • One is reduced to the figures of the real estate "booster" for terms of proportion.


    Mary Austin

  • "Be a Booster," it advises, and no one can say that it does not live up to its principles.

    Abroad at Home

    Julian Street

British Dictionary definitions for booster


  1. a person or thing that supports, assists, or increases power or effectiveness
  2. Also called: launch vehicle the first stage of a multistage rocket
  3. radio television
    1. a radio-frequency amplifier connected between an aerial and a receiver to amplify weak incoming signals
    2. a radio-frequency amplifier that amplifies incoming signals, retransmitting them at higher power
  4. another name for supercharger
  5. short for booster dose
  6. slang, mainly US a shoplifter
Collins English Dictionary - Complete & Unabridged 2012 Digital Edition © William Collins Sons & Co. Ltd. 1979, 1986 © HarperCollins Publishers 1998, 2000, 2003, 2005, 2006, 2007, 2009, 2012

Word Origin and History for booster

1890, "one who boosts" something, agent noun from boost (v.). Electrical sense is recorded from 1894. Young child's booster chair is attested under that name from 1960.

Online Etymology Dictionary, © 2010 Douglas Harper

booster in Medicine


  1. An additional dose of an immunizing agent, such as a vaccine or toxoid, given at a time after the initial dose to sustain the immune response elicited by the previous dose of the same agent.booster dose booster shot
The American Heritage® Stedman's Medical Dictionary Copyright © 2002, 2001, 1995 by Houghton Mifflin Company. Published by Houghton Mifflin Company.

booster in Science


  1. An additional dose of an immunizing agent, such as a vaccine or toxoid, given at a time period of weeks to years after the initial dose to sustain the immune response elicited by the first dose. Tetanus, diphtheria, and measles vaccines are commonly given in booster doses.
The American Heritage® Science Dictionary Copyright © 2011. Published by Houghton Mifflin Harcourt Publishing Company. All rights reserved.