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

Eligible items for the Target car seat trade-in program include infant car seats, convertible car seats, car seat bases, harness or booster car seats, as well as car seats that are expired or damaged. —Marina Johnson, The Courier-Journal, 9 Apr. 2024

While this would be the fulfillment of a dream that many civic boosters have had since the minor league River Cats franchise moved into its home in West Sacramento, both Matheson and Maxcy warned that all that glitters is not necessarily gold. —Cathie Anderson, Sacramento Bee, 6 Apr. 2024

It is recommended for children ages 11 to 12, and because protection wanes, a booster is usually given at age 16. —Cnn.com Wire Service, The Mercury News, 29 Mar. 2024

Even with these popular destinations lining its sidewalks, the Grand — and downtown in general — has not transformed into the thriving center of urban living that boosters had hoped for. —Jessica Gelt, Los Angeles Times, 27 Mar. 2024

Blazer described how the system really worked, with the coaches, sneaker companies, agents, financial advisors, boosters and unsavory hustlers and runners engaged in vast conspiracies to evade the rules of amateurism. —Guy Lawson, Rolling Stone, 24 Mar. 2024

Your go-to energy booster might be a creepy true crime podcast that gets your adrenaline pumping. —Jenna Ryu, SELF, 22 Mar. 2024

All 33 of the booster’s engines started up successfully and completed a full-duration burn during ascent, per SpaceX. —Will Sullivan, Smithsonian Magazine, 15 Mar. 2024

In Falcon 9 rockets, the first-stage booster is a reusable component meant to propel the rocket out of the atmosphere before detaching and landing on Earth. —Madeline Nguyen, The Arizona Republic, 29 Mar. 2024

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