let in vs let

let in is not a noun while let is a noun.

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

As verbs, let is a hypernym of let in; that is, let is a word with a broader meaning than let in:

let in: allow participation in or the right to be part of; permit to exercise the rights, functions, and responsibilities of
let: consent to, give permission; permit

Other hypernyms of let in include allow, countenance, permit.

As verbs, let is a hypernym of let in; that is, let is a word with a broader meaning than let in:

Other hypernyms of let in include allow, countenance, permit.

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

let in (verb)	let (verb)
allow participation in or the right to be part of; permit to exercise the rights, functions, and responsibilities of	leave unchanged
allow to enter; grant entry to	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