undermine vs hollow

undermine is not a noun while hollow is a noun.

Word	Noun	Adjective	Verb	Adverb
undermine	No	No	Yes	No
hollow	Yes	Yes	Yes	No

As verbs, hollow is a hypernym of undermine; that is, hollow is a word with a broader meaning than undermine:

Other hypernyms of undermine include core out, hollow out.

undermine (noun)	hollow (noun)
	a depression hollowed out of solid matter
	a small valley between mountains
	a cavity or space in something

undermine (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

undermine (verb)	hollow (verb)
hollow out as if making a cave or opening	remove the interior of
destroy property or hinder normal operations	remove the inner part or the core of