boost·​er | \ ˈbü-stər How to pronounce booster (audio) \

Definition of booster

: one that boosts: such as
a : an enthusiastic supporter
b : an auxiliary device for increasing force, power, pressure, or effectiveness
c slang : shoplifter
d : a radio-frequency amplifier for a radio or television receiving set
e : the first stage of a multistage rocket providing thrust for the launching and the initial part of the flight
f : a substance or dose used to renew or increase the effect of a drug or immunizing agent especially : booster shot

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Examples of booster in a Sentence

These exercises are real metabolism boosters. Music is my favorite mood booster. A sincere compliment can be a true confidence booster. The university has a number of wealthy boosters who contribute generously each year. a new design for rocket boosters
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Recent Examples on the Web

Three for three boosters today on Falcon Heavy, what an amazing accomplishment. Marcia Dunn, The Seattle Times, "SpaceX launches mega rocket, lands all 3 boosters," 14 Apr. 2019 Update: SpaceX successfully landed all three boosters on today's flight. Avery Thompson, Popular Mechanics, "SpaceX Lands All Three Falcon Heavy Boosters for the First Time," 10 Apr. 2019 Because those boosters were limited to two missions, SpaceX did not attempt to land the stage for a second time. James Dean, USA TODAY, "SpaceX Falcon rocket blasts off with robot crew member," 29 June 2018 Research from Knox College found that listening to upbeat music is a major mood booster. Kelly Mickle, Woman's Day, "11 Sleeping Tips To Help You Wake Up in the Best Mood," 4 Aug. 2016 The group’s chief architect, former Brazilian President Luiz Inacio Lula da Silva, is in jail on corruption charges while another big booster, Venezuela’s Hugo Chavez, has died. Joshua Goodman, The Seattle Times, "South America bloc’s woes leave architectural gem forlorn," 8 Jan. 2019 Further Reading As the SpaceX steamroller surges, European rocket industry vows to resist So far, Arianespace has launched 10 rockets this year: six Ariane 5 boosters, two Vega rockets, and two Soyuz medium-lift rockets. Eric Berger, Ars Technica, "Tuesday may deliver a triple-header of big launches to cap 2018," 17 Dec. 2018 And then, at 3:31 a.m. EDT (0731 GMT), that dark sky lit up in a flash of brilliant orange as a United Launch Alliance Delta IV Heavy rocket, one of the most powerful boosters flying today, lifted off the pad. Mike Wall,, "A Fireball and a Wall of Sound: What NASA's Epic Solar Probe Launch Felt Like," 14 Aug. 2018 Jimmer Fredette, Bobby Brown and Royce White are playing, while Frank Mason III and Anthony Tolliver, who spent last season with the Detroit Pistons, are listed as boosters. Noel Harris, sacbee, "How Matt Barnes and others with ties to the Kings are vying to win $2 million," 14 June 2018

These example sentences are selected automatically from various online news sources to reflect current usage of the word 'booster.' Views expressed in the examples do not represent the opinion of Merriam-Webster or its editors. Send us feedback.

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First Known Use of booster

1888, in the meaning defined above

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Statistics for booster

Last Updated

30 Apr 2019

Look-up Popularity

Time Traveler for booster

The first known use of booster was in 1888

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More Definitions for booster



English Language Learners Definition of booster

: an action or substance that makes something stronger or more effective
: something that helps or encourages someone or something
US : someone who supports an idea or organization


boost·​er | \ ˈbü-stər How to pronounce booster (audio) \

Medical Definition of booster

: a substance or dose used to renew or increase the effect of a drug or immunizing agent: such as
a(1) : booster shot
(2) : booster dose
b : synergist sense 1 a chemical acting as a booster to sulfa drugs

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More from Merriam-Webster on booster

Thesaurus: All synonyms and antonyms for booster

Spanish Central: Translation of booster

Nglish: Translation of booster for Spanish Speakers

Comments on booster

What made you want to look up booster? Please tell us where you read or heard it (including the quote, if possible).


a strong desire or propensity

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