Enigma
Enigma (noun) means a person or thing that is puzzling, mysterious, or hard to understand. Example: “His sudden disappearance remains an enigma to this day.”
How to use Enigma
Learner’s notesIn plain EnglishSomething or someone genuinely puzzling or mysterious.
Fill the gap
Can you complete this real example?
His sudden disappearance remains an _____ to this day.
Etymology
Comes from Latin aenigma (“riddle”), which itself derives from the Ancient Greek verbal noun αἴνιγμα (aínigma, “dark saying, speaking in riddles”).