hem vs let loose

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

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

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

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

hem (noun)	let loose (noun)
the edge of a piece of cloth; especially the finished edge that has been doubled under and stitched down
the utterance of a sound similar to clearing the throat; intended to get attention, express hesitancy, fill a pause, hide embarrassment, warn a friend, etc.

hem (verb)	let loose (verb)
utter `hem' or `ahem'	express audibly; utter sounds (not necessarily words)
fold over and sew together to provide with a hem	turn loose or free from restraint