enigma

Từ điển WordNet v3.1 - WordNet Dictionary

noun

1. something that baffles understanding and cannot be explained (Freq. 1)
- how it got out is a mystery
- it remains one of nature's secrets
• Syn:
mystery, secret, closed book
• Derivationally related forms:
enigmatic, enigmatical, mysterious (for: mystery), mystify (for: mystery)
• Hypernyms:
perplexity
2. a difficult problem
• Syn:
riddle, conundrum, brain-teaser
• Derivationally related forms:
riddle (for: riddle)
• Hypernyms:
problem

• Từ đồng nghĩa / Synonyms:
  riddle, conundrum, brain-teaser, mystery, secret, closed book