cave vs explore

cave is a noun but explore is not a noun.

Word	Noun	Adjective	Verb	Adverb
cave	Yes	No	Yes	No
explore	No	No	Yes	No

As verbs, explore is a hypernym of cave; that is, explore is a word with a broader meaning than cave:

cave (noun)	explore (noun)
a geological formation consisting of an underground enclosure with access from the surface of the ground or from the sea

cave (verb)	explore (verb)
explore natural caves	inquire into
hollow out as if making a cave or opening	travel to or penetrate into
	inquire into a subject in detail
	examine (organs) for diagnostic purposes