rabbit hole vs hollow

rabbit hole and hollow both are nouns.

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

As nouns, hollow is a hypernym of rabbit hole; that is, hollow is a word with a broader meaning than rabbit hole:

Other hypernyms of rabbit hole include hole.

rabbit hole (noun)	hollow (noun)
a hole in the ground as a nest made by wild rabbits	a depression hollowed out of solid matter
	a small valley between mountains
	a cavity or space in something

rabbit hole (adjective)	hollow (adjective)
	not solid; having a space or gap or cavity
	lacking in substance or character
	devoid of significance or force
	as if echoing in a hollow space

rabbit hole (verb)	hollow (verb)
	remove the interior of
	remove the inner part or the core of