verifier vs booster

verifier and booster both are nouns.

Word	Noun	Adjective	Verb	Adverb
verifier	Yes	No	No	No
booster	Yes	No	No	No

As nouns, booster is a hypernym of verifier; that is, booster is a word with a broader meaning than verifier:

verifier: someone who vouches for another or for the correctness of a statement
booster: a person who backs a politician or a team etc.

Other hypernyms of verifier include admirer, champion, friend, protagonist, supporter.

verifier (noun)	booster (noun)
someone who vouches for another or for the correctness of a statement	an additional dose that makes sure the first dose was effective
	the first stage of a multistage rocket
	an amplifier for restoring the strength of a transmitted signal
	a thief who steals goods that are in a store
	someone who is an active supporter and advocate
	a person who backs a politician or a team etc.