名詞 enigma:

1. something that baffles understanding and cannot be explained
   同義詞：mystery, secret, closed book
2. a difficult problem
   同義詞：riddle, conundrum, brain-teaser

1. It is an enigma to me.
   它對我來說是個迷。
2. He is an enigma to all of us.
   對我們而言，他是個神秘莫測的人物。
3. Russia is a riddle wrapped in a mystery inside an enigma.
   俄羅斯是被包藏在一個悶胡蘆里面的神秘物體之中的謎。

e.nig.ma

n.（名詞）
One that is puzzling, ambiguous, or inexplicable.
謎：讓人困惑、模糊、難以說清楚的物或人
A perplexing speech or text; a riddle.
謎語：令人困惑不清的話或文字；謎語

來源：
Latin aenigma
拉丁語 aenigma
from Greek ainigma
源自 希臘語 ainigma
from ainissesthai ainig- [to speak in riddles]
源自 ainissesthai ainig- [說謎語]
from ainos [fable]
源自 ainos [寓言]