mystery vs enigma

mystery and enigma both are nouns.

Word	Noun	Adjective	Verb	Adverb
mystery	Yes	No	No	No
enigma	Yes	No	No	No

As nouns, mystery and enigma are synonyms defined as:

mystery and enigma: something that baffles understanding and cannot be explained

Other synonyms of mystery include closed book, secret.

mystery (noun)	enigma (noun)
something that baffles understanding and cannot be explained	something that baffles understanding and cannot be explained
a story about a crime (usually murder) presented as a novel or play or movie	a difficult problem