repeat vs let out

repeat is a noun but let out is not a noun.

Word	Noun	Adjective	Verb	Adverb
repeat	Yes	No	Yes	No
let out	No	No	Yes	No

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

Other hypernyms of repeat include emit, let loose, utter.

repeat (noun)	let out (noun)
an event that repeats

repeat (verb)	let out (verb)
happen or occur again	make (clothes) larger
to say, state, or perform again	make known to the public information that was previously known only to a few people or that was meant to be kept a secret
to say again or imitate	express audibly; utter sounds (not necessarily words)
make or do or perform again	bring out of a specific state
repeat an earlier theme of a composition
do over