Latin aenigma, from Greek ainigmat-, ainigma, from ainissesthai to speak in riddles, from ainos fable
noun
something hard to understand or explain
an inscrutable or mysterious person
an obscure speech or writing
mysteryproblemenigmariddlepuzzle mean something which baffles or perplexes. mystery applies to what cannot be fully understood by reason or less strictly to whatever resists or defies explanation. problem applies to a question or difficulty calling for a solution or causing concern.