An enigma (from Greek αἴνιγμα, plural enigmas or enigmata) is a puzzle, something mysterious or inexplicable, or a riddle or difficult problem. The word can also be used to describe a mysterious or secretive person.
Because humans have a natural sense of curiosity, an enigma is often a topic of intense interest, discussion, and debate before it is solved. Some famous historical enigmas have captivated the imagination of some of the greatest minds in the world, and continue to do so, as is the case with Fermat’s last theorem in mathematics. Some people relish the intellectual challenge of an enigma, as it allows them to prove their intellectual capabilities to themselves and others.
Someone who speaks in riddles may be called “enigmatic.” Many examples of enigmatic individuals can be found in history and in literature; such individuals are sometimes treated as great minds, since it is assumed that their brains simply work too quickly to allow normal individuals to comprehend them.