bray vs let out

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

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

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

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

bray (noun)	let out (noun)
the cry of an ass

bray (verb)	let out (verb)
laugh loudly and harshly	make (clothes) larger
reduce to small pieces or particles by pounding or abrading	make known to the public information that was previously known only to a few people or that was meant to be kept a secret
braying characteristic of donkeys	express audibly; utter sounds (not necessarily words)
	bring out of a specific state