prevent vs let

prevent is not a noun while let is a noun.

Word	Noun	Adjective	Verb	Adverb
prevent	No	No	Yes	No
let	Yes	No	Yes	No

prevent (noun)	let (noun)
	a serve that strikes the net before falling into the receiver's court; the ball must be served again

prevent (verb)	let (verb)
stop (someone or something) from doing something or being in a certain state	leave unchanged
keep from happening or arising; make impossible	cause to move; cause to be in a certain position or condition
	actively cause something to happen
	consent to, give permission; permit
	grant use or occupation of under a term of contract
	make it possible through a specific action or lack of action for something to happen