a person, thing or situation that is mysterious and difficult to understand synonym mystery, puzzle Even after years he still remains an enigma to me. Word Origin mid 16th cent.: via Latin from Greek ainigma
‘riddle’, from ainissesthai ‘speak allusively’, from ainos ‘fable’.Extra examples Madeleine was still very much an enigma to him. Nobody really knows the answer. It’s something of an enigma. Even after all these years he still remains an enigma to me. The enigma of the giant stones draws visitors from around the world. The tower presents an enigma. How old is it? Who built it?