Enigma (noun)
en-ig-ma
A person of puzzling or contradictory character.
Enigma was first recorded in English around 1530–40 and comes from the Greek word aínigma, “riddle,” which derived from aînos, “fable.” Enigma was also the name of a ciphering machine used by the German military during World War II. A precursor to computer encryption, the Enigma machine encoded messages into a seemingly random string of letters to be decoded by another Enigma machine.
Example sentences
“I don’t understand her behaviour at all, she’s a complete enigma.”