boost·​er | \ ˈbü-stər \

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

While the Ariane 6 gets its name from following the Ariane 5, the 64 comes from this version have four strap-on boosters. David Grossman, Popular Mechanics, "The ESA Is Taking Steps to Mine Moon Dust," 23 Jan. 2019 Its most famous claim to fame, though, is as a natural libido booster. Caroline Picard, Good Housekeeping, "Does Maca Powder Have Health Benefits for Women? Here's What the Science Says," 14 Jan. 2019 Gatorade, for instance, is often cited as a lactation booster, though opinions on mom forums vary as to which flavor is more effective — some are in the blue camp, while others are squarely in the orange. E.j. Dickson, Vox, "Inside the mommy-friendly, scientifically sketchy world of breastfeeding supplements," 20 Dec. 2018 Reasons range from changing designs to SpaceX’s being shut out earlier this year from a U.S. Air Force competition that awarded more than $2 billion in contracts to three other rocket makers to develop various smaller boosters. Rob Copeland, WSJ, "Elon Musk’s SpaceX Is Raising $500 Million in Funding," 18 Dec. 2018 For this mission, SpaceX is employing another one of its used rockets, a Falcon 9 booster that launched the Telstar 19 VANTAGE satellite in July. Loren Grush, The Verge, "Watch SpaceX launch and land a used Falcon 9 rocket," 15 Nov. 2018 Provide light and infrequent feedings with a blossom booster or low nitrogen type of fertilizer. Tom Maccubbin,, "Summer heat, rain not kind to geraniums," 30 June 2018 He was banished from Michigan's campus for 10 years after being implicated in a NCAA investigation for accepting improper benefits from booster Ed Martin. Jenna West,, "Chris Webber Accepts Jim's Harbaugh's Invitation to Be Michigan's Honorary Football Captain," 23 June 2018 Fenugreek seed, as Mowry also mentioned in her Instagram caption, has been touted as a magical milk supply booster The seed is ground into capsules, powders, teas, and liquid extracts. Taylyn Washington-harmon, SELF, "Tia Mowry Says These Foods Help Keep Up Her Milk Supply," 22 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

5 Feb 2019

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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 \

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).


to deny responsibility for

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