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

Keep scrolling for more

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
See More
Recent Examples on the Web Introducing the Yenisei While downsizing rocket boosters seems counterintuitive when designing such a big rocket, the cluster approach does offer some distinct advantages. Anatoly Zak, Popular Mechanics, "Everything You Need To Know About Russia’s (Possibly Fictional) Super Heavy Rocket," 3 Feb. 2020 With high school participation in 11-man football in decline, the N.F.L. and the sport’s boosters are touting new equipment, better medical treatment and rules changes that remove some of the most dangerous elements. Ken Belson, New York Times, "The Perfect ’72 Dolphins and Football’s Ultimate Toll," 30 Jan. 2020 Debris from satellites or rocket boosters colliding or exploding in orbit is an increasing concern in the space community. Jackie Wattles, CNN, "DirecTV rushes to dispose of satellite that might explode," 24 Jan. 2020 The caution expressed in Maine indicates TCI’s boosters might still have some persuading to do. Jon Chesto,, "Mills becomes latest governor to express concern about regional fuel pact," 13 Jan. 2020 For decades in college recruiting circles, there have been legends about the complex ways that boosters funnel money to recruits, including charitable foundations. Dan Wolken, USA TODAY, "Opinion: LSU booster scandal barely registering blip on radar is sign of times," 13 Jan. 2020 To remedy that shortcoming, the Pentagon plans to launch hundreds of small satellites with sensors capable of tracking heat sources an order of magnitude cooler than rocket boosters. Richard Stone, Science | AAAS, "‘National pride is at stake.’ Russia, China, United States race to build hypersonic weapons," 8 Jan. 2020 There, large solid-rocket boosters will be attached to the side of the vehicle before the upper stage and Orion spacecraft are strapped on in anticipation of the uncrewed Artemis 1 mission. Eric Berger, Ars Technica, "Boeing finally completes SLS core stage, packs it for Mississippi tests," 8 Jan. 2020 The athletic departments get boosters involved and work tirelessly to fundraise. Luis Torres,, "FAMU, B-CU count on Florida Classic to help with constant battle for funding," 23 Nov. 2019

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.

See More

First Known Use of booster

1888, in the meaning defined above

Keep scrolling for more

Learn More about booster

Time Traveler for booster

Time Traveler

The first known use of booster was in 1888

See more words from the same year

Statistics for booster

Last Updated

19 Feb 2020

Cite this Entry

“Booster.” Dictionary, Merriam-Webster, Accessed 24 Feb. 2020.

Keep scrolling for more

More Definitions for booster


How to pronounce booster (audio)

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
b : synergist sense 1 a chemical acting as a booster to sulfa drugs

Keep scrolling for more

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).


See Definitions and Examples »

Get Word of the Day daily email!

Test Your Vocabulary

More Confusing Words—Quiz

  • cats on impossible timber
  • The magician ______ moved the selected card to the top of the deck.
Spell It

Can you spell these 10 commonly misspelled words?


Test Your Knowledge - and learn some interesting things along the way.

Love words? Need even more definitions?

Subscribe to America's largest dictionary and get thousands more definitions and advanced search—ad free!