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noun Uncommon

booster

BOOST

Booster (noun) means an additional dose of a vaccine given to renew or strengthen immunity. Example: “He got his flu booster in early autumn.”

noun
1
An additional dose of a vaccine given to renew or strengthen immunity.
"He got his flu booster in early autumn."
2
A device or component that increases power, signal, or force.
"They installed a signal booster to fix the weak Wi-Fi in the garage."
3
A person who actively supports or promotes something.
"She has always been a booster for her hometown's small businesses."

How to use booster

Learner’s notes

In plain EnglishSomething (or someone) that adds extra strength, power, or support.

Common pairings
booster shot signal booster rocket booster

Word forms

boostered past tense, boosters singular

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Test yourself on “booster” A quick quiz — meaning, synonyms & usage

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Can you complete this real example?

He got his flu _____ in early autumn.

Etymology

Formed from the verb "boost" plus the agent suffix "-er."

Related words

Rhymes for booster

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Frequently asked questions

What does “booster” mean?

The word “booster” means an additional dose of a vaccine given to renew or strengthen immunity. In plain terms, something (or someone) that adds extra strength, power, or support.

How do you pronounce “booster”?

“Booster” is pronounced BOOST (/ˈbustɚ/ in IPA).

How do you use “booster” in a sentence?

Here is “booster” used in a sentence: “He got his flu booster in early autumn.”

What part of speech is “booster”?

“Booster” is a noun.

Is “booster” a common word?

“Booster” is an uncommon word in modern English.

How many meanings does “booster” have?

“Booster” has 3 distinct senses listed in this dictionary. The most common is: an additional dose of a vaccine given to renew or strengthen immunity.

What is the difference between a booster shot and a regular vaccine dose?

A regular vaccine dose is part of the initial immunization series meant to establish immunity, while a booster shot is an additional dose given later to renew or strengthen immunity that may have weakened over time. Boosters are typically administered after the initial series has already provided a baseline level of protection.

What is the difference between a booster and an amplifier when talking about signals?

A booster increases the power, signal, or force of something, such as a Wi-Fi signal or rocket stage, generally to extend range or strength. An amplifier specifically increases the amplitude of an electronic signal, most often used in audio contexts, making it a more specialized type of booster.

Can booster refer to a person rather than a device or vaccine dose?

Yes, booster can also describe a person who actively supports or promotes something, such as a local booster who champions their community or a sports team. This sense is distinct from the medical or mechanical meanings but shares the underlying idea of increasing strength or support.

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Definitions: FreeDict original editorial