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

If boosters can improve NIL salaries – Northwestern is said to have half of Ohio State's $50-$55M NIL budget – watch out. — Joe Kinsey Outkick, FOXNews.com, 3 Oct. 2026

To add an extra flourish to the launch triple-header, SpaceX returned both Falcon 9 boosters to their launch sites in Florida and California and landed both side boosters from Falcon Heavy back at Cape Canaveral Space Force Station. — Stephen Clark, ArsTechnica, 2 Oct. 2026

Silva was hired by the team booster club to take the photos, which were intended to be enjoyed by the players and their family. — Clara Harter, Los Angeles Times, 30 Sep. 2026

Cottonseed boosters proclaimed a transformation of waste into wealth. — Edward D. Melillo, The Conversation, 30 Sep. 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