adventurer vs explorer

adventurer and explorer both are nouns.

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

As nouns, adventurer and explorer are synonyms defined as:

adventurer and explorer: someone who travels into little known regions (especially for some scientific purpose)

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