booster

noun

boost·​er ˈbü-stər 

: 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

Synonyms of booster

• proponent
• supporter
• advocate
• advocator
• exponent
• promoter

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

Recent Examples on the Web

Well, Texas Tech's most prominent booster, Cody Campbell, has some very pointed comments for those schools, conferences, or institutions considering taking action against the program. —Ian Miller Outkick, FOXNews.com, 11 June 2026

College coaches, administrators and prominent boosters all over the state, and nation, are furious at Texas Tech football coach Joey McGuire, Texas Tech athletic director Kirby Hocutt, and Texas Tech booster Cody Campbell. —Fort Worth Star-Telegram, 11 June 2026

That is because the appropriate schedule for giving RSV booster shots is still unclear. —Helen Branswell, STAT, 10 June 2026

But as this investment is finally coming to fruition, ULA has suspended Vulcan launches to investigate a recurring problem with its strap-on solid rocket boosters. —Stephen Clark, ArsTechnica, 9 June 2026

Word History

First Known Use

1888, in the meaning defined above

Phrases Containing booster

• booster chair
• booster cushion
• booster dose
• booster seat
• booster shot

Rhymes for booster

• rooster

Kids Definition

booster

noun

boost·​er ˈbü-stər 

1

: one that boosts

2

: an enthusiastic supporter

3

: booster shot

4

: a device for strengthening radio or television signals

5

: the first stage of a multistage rocket providing force for the launching and the first part of the flight

Medical Definition

booster

noun

boost·​er ˈbü-stər 

: 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