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

• advocate
• advocator
• apostle
• backer
• champion
• espouser
• exponent
• expounder
• friend
• gospeler
• gospeller
• herald
• hierophant
• high priest
• paladin
• promoter
• proponent
• protagonist
• supporter
• true believer
• tub-thumper
• white knight

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

The first-stage booster that had been tapped during the original attempts was discarded for a new booster. —Richard Tribou, Orlando Sentinel, 15 Jan. 2025

In November, SpaceX launched the same Falcon 9 booster twice in less than 14 days, the shortest turnaround time for a booster yet. —Stephen Clark, Ars Technica, 14 Jan. 2025

The goal of the mission is to land New Glenn's first-stage booster on a floating platform in the Atlantic about 10 minutes after liftoff, while the rocket's second stage continues toward orbit. —John Mac Ghlionn, Newsweek, 14 Jan. 2025

Advertisement The test flight already had been delayed by rough seas that posed a risk to the company’s plan to land the first-stage booster on a floating platform in the Atlantic Ocean. —Marcia Dunn, Los Angeles Times, 13 Jan. 2025

Word History

First Known Use

1888, in the meaning defined above

Phrases Containing booster

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

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