The Latin adjective fanaticus, a derivative of the noun fanum, meaning “temple,” originally meant “of or relating to a temple.” It was later used to refer to pious individuals who were thought to have been inspired by a god or goddess. In time, the sense “frantic, frenzied, mad” arose because it was thought that persons behaving in such a manner were possessed by a deity. This was the first meaning of the English word fanatic. This sense is now obsolete, but it led to the meaning “excessively enthusiastic, especially about religious matters.” The word later became less specific, meaning simply “excessively enthusiastic or unreasonable.” The noun fan, meaning “enthusiast,” is probably a shortening of fanatic.