ENIGMA
mystery, enigma, secret, closed book
(noun) something that baffles understanding and cannot be explained; “how it got out is a mystery”; “it remains one of nature’s secrets”
riddle, conundrum, enigma, brain-teaser
(noun) a difficult problem
Source: WordNet® 3.1
Proper noun
Enigma
(historical) A German device used during World War II to encode strategic messages.
Anagrams
• gamine, imagen, in-game
Etymology
Noun
enigma (plural enigmas or enigmata)
Something or someone puzzling, mysterious or inexplicable.
A riddle, or a difficult problem.
Anagrams
• gamine, imagen, in-game
Source: Wiktionary
E*nig"ma, n.; pl. Enigmas. Etym: [L. aenigma, Gr.
1. A dark, obscure, or inexplicable saying; a riddle; a statement,
the hidden meaning of which is to be discovered or guessed.
A custom was among the ancients of proposing an enigma at festivals.
Pope.
2. An action, mode of action, or thing, which cannot be
satisfactorily explained; a puzzle; as, his conduct is an enigma.
Source: Webster’s Unabridged Dictionary 1913 Edition