51 entries under expression topic. ×

4
sixty-four dollar question(noun, idiom, question, secret)
4
subject of controversy(noun, idiom, question, secret)
4
subject of inquiry(noun, idiom, question, secret)
3
classified information(idiom, confidence, secret, mystery)
3
frontiers of knowledge(idiom, secret, mystery, brain-twister)
3
matter of ignorance(idiom, secret, mystery, brain-twister)
3
mysterious puzzle(idiom, secret, mystery, brain-twister)
3
mystery of mysteries(idiom, secret, mystery, brain-twister)
2
baffling mystery(idiom, secret, mystery, brain-twister)
2
baffling problem(idiom, secret, mystery, brain-twister)
2
confidential communication(idiom, secret, mystery, brain-twister)
2
dark horse(idiom, secret, mystery, brain-twister)
2
enigmatic question(idiom, secret, mystery, brain-twister)
2
guarded secret(idiom, secret, mystery, brain-twister)
2
perplexed question(idiom, secret, mystery, brain-twister)
2
private matter(idiom, secret, mystery, brain-twister)
2
privileged communication(idiom, secret, mystery, brain-twister)
2
profound secret(idiom, secret, mystery, brain-twister)
2
puzzling thing(idiom, secret, mystery, brain-twister)
2
restricted information(idiom, secret, mystery, brain-twister)
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APASmart Define. (2016). enigma thesaurus. Retrieved September 21, 2026, from https://smartdefine.org/enigma/thesaurus/synonyms
ChicagoSmart Define. 2016. "enigma thesaurus" https://smartdefine.org/enigma/thesaurus/synonyms (accessed September 21, 2026).
HarvardSmart Define 2016, enigma thesaurus, Smart Define, viewed 21 September, 2026, <https://smartdefine.org/enigma/thesaurus/synonyms>.
MLASmart Define. "enigma thesaurus" 1 April 2016. Web. 21 September 2026. <https://smartdefine.org/enigma/thesaurus/synonyms>