gurgle vs let out

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

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

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

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

gurgle (noun)	let out (noun)
the bubbling sound of water flowing from a bottle with a narrow neck

gurgle (verb)	let out (verb)
utter with a gurgling sound	make (clothes) larger
drink from a flask with a gurgling sound	make known to the public information that was previously known only to a few people or that was meant to be kept a secret
flow in an irregular current with a bubbling noise	express audibly; utter sounds (not necessarily words)
make sounds similar to gurgling water	bring out of a specific state