haw vs let loose

haw is a noun but let loose is not a noun.

Word	Noun	Adjective	Verb	Adverb
haw	Yes	No	Yes	No
let loose	No	No	Yes	No

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

Other hypernyms of haw include emit, let out, utter.

haw (noun)	let loose (noun)
the nictitating membrane of a horse
a spring-flowering shrub or small tree of the genus Crataegus

haw (verb)	let loose (verb)
utter `haw'	express audibly; utter sounds (not necessarily words)
	turn loose or free from restraint