hollow out vs hole

hollow out is not a noun while hole is a noun.

Word	Noun	Adjective	Verb	Adverb
hollow out	No	No	Yes	No
hole	Yes	No	Yes	No

As verbs, hole is a hyponym of hollow out; that is, hole is a word with a more specific, narrower meaning than hollow out:

hollow out (noun)	hole (noun)
	an opening deliberately made in or through something
	one playing period (from tee to green) on a golf course
	informal terms for the mouth
	an opening into or through something
	a depression hollowed out of solid matter
	an unoccupied space
	informal terms for a difficult situation
	a fault

hollow out (verb)	hole (verb)
remove the interior of	make holes in
	hit the ball into the hole