Someone who is really into something (or someone). The word's origins are from a shortened form of "fanatic"; "fan" implies the dedication, but doesn't have so many negative implications. (On the other hand, the word "fanatic" originally merely meant "one who is inspired by religious zeal"; given the heights to which some fans take their devotion, that definition is not entirely inaccurate.) One can be a fan of something (or someone) for a multitude of reasons. Perhaps it is incredibly good,