Quiz: Remember the definition of mal de mer?


[boo-ster] /ˈbu stər/
a person or thing that boosts, especially an energetic and enthusiastic supporter.
Electricity. a device connected in series with a current for increasing or decreasing the nominal circuit voltage.
Railroads. any machine, device, phenomenon, etc., that helps to move a train, as a tailwind, downgrade, roller bearings, or especially a helper locomotive.
Military. an explosive more powerful than a primer, for ensuring the detonation of the main charge of a shell.
  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.
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.
Pharmacology. a chemical compound, medicinal substance, or the like, that serves as a synergist.
a radio-frequency amplifier for connecting between a radio or television antenna and the receiving set to intensify the received signal.
an auxiliary pump, used in a pipeline or other system, to add to or maintain a prevailing amount of pressure or vacuum.
Slang. a shoplifter or petty thief.
1885-90, Americanism; boost + -er1
Related forms
boosterish, adjective Unabridged
Based on the Random House Dictionary, © Random House, Inc. 2015.
Cite This Source
Examples from the web for booster
  • The left solid rocket booster continues to fly, still thrusting.
  • But it's being marketed as a booster for a kind of workout you won't find at the gym.
  • Consortium agronomists are growing plants such as ginseng, a reputed circulation booster, in wooded areas.
  • Bias intimidation is a sentence-booster that attaches itself to an underlying crime-usually, a violent one.
  • The thing is a dry battery with a booster coil, both so small that together they fit into the palm of one's hand.
  • But rare is the booster dedicated enough to take out a vanity plate.
  • Encouraging office chat invites the same over-sharing of information that turns email from a productivity-booster to a time-suck.
  • He was giving a blood, sweat, and tears booster shot.
  • If not stopped in time, with a booster shot of drugs, the destruction succeeds and the organ is rejected.
  • But prices are likely to keep falling this year, so economic recovery will lack one of its usual booster rockets.
British Dictionary definitions for booster


a person or thing that supports, assists, or increases power or effectiveness
Also called launch vehicle. the first stage of a multistage rocket
(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
another name for supercharger
short for booster dose
(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
Cite This Source
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
Cite This Source
booster in Medicine

booster boost·er (bōō'stər)
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. Also called booster dose, booster shot.

The American Heritage® Stedman's Medical Dictionary
Copyright © 2002, 2001, 1995 by Houghton Mifflin Company. Published by Houghton Mifflin Company.
Cite This Source
booster in Science
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 © 2002. Published by Houghton Mifflin. All rights reserved.
Cite This Source
Slang definitions & phrases for booster


  1. A shoplifter; pilferer: Got a booster for you. The chunky girl in blue at the lace counter/ He knew they couldn't be boosters or creepers (1908+)
  2. A huckster's or auctioneer's assistant who pretends to buy in order to stimulate others; shill (1905+ Carnival)
  3. A person who praises extravagantly; fan (1890+)

The Dictionary of American Slang, Fourth Edition by Barbara Ann Kipfer, PhD. and Robert L. Chapman, Ph.D.
Copyright (C) 2007 by HarperCollins Publishers.
Cite This Source
booster in Technology

A data-parallel language.
"The Booster Language", E. Paalvast, TR PL 89-ITI-B-18, Inst voor Toegepaste Informatica TNO, Delft, 1989.
The Free On-line Dictionary of Computing, © Denis Howe 2010
Cite This Source

Word of the Day

Difficulty index for booster

Most English speakers likely know this word

Word Value for booster

Scrabble Words With Friends

Quotes with booster

Nearby words for booster