noun
booster
BOOST
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 notesIn 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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He got his flu _____ in early autumn.
Etymology
Formed from the verb "boost" plus the agent suffix "-er."