spelunker vs adventurer

spelunker and adventurer both are nouns.

Word	Noun	Adjective	Verb	Adverb
spelunker	Yes	No	No	No
adventurer	Yes	No	No	No

As nouns, adventurer is a hypernym of spelunker; that is, adventurer is a word with a broader meaning than spelunker:

spelunker: a person who explores caves
adventurer: someone who travels into little known regions (especially for some scientific purpose)

Other hypernyms of spelunker include explorer.

spelunker (noun)	adventurer (noun)
a person who explores caves	a person who enjoys taking risks
	someone who travels into little known regions (especially for some scientific purpose)