adventurer vs frogman

adventurer and frogman both are nouns.

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

As nouns, frogman is a hyponym of adventurer; that is, frogman is a word with a more specific, narrower meaning than adventurer:

adventurer: someone who travels into little known regions (especially for some scientific purpose)
frogman: someone who works underwater

adventurer (noun)	frogman (noun)
a person who enjoys taking risks	someone who works underwater
someone who travels into little known regions (especially for some scientific purpose)