wolf-whistle vs let out

wolf-whistle and let out both are verbs.

Word	Noun	Adjective	Verb	Adverb
wolf-whistle	No	No	Yes	No
let out	No	No	Yes	No

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

Other hypernyms of wolf-whistle include emit, let loose, utter.

wolf-whistle (verb)	let out (verb)
whistle or howl approvingly at a female, of males	make (clothes) larger
	make known to the public information that was previously known only to a few people or that was meant to be kept a secret
	express audibly; utter sounds (not necessarily words)
	bring out of a specific state