Definitions of fan:

noun: a device for creating a current of air by movement of a surface or surfaces
noun: an ardent follower and admirer
noun: an enthusiastic devotee of sports
verb: make (an emotion) fiercer
Example: "Fan hatred"
verb: strike out (a batter), (of a pitcher)
verb: agitate the air
verb: separate from chaff
name: A surname (rare: 1 in 100000 families; popularity rank in the U.S.: #9705)