Real Dictionary

fan
If you are a fan of someone or something, especially a famous person or a sport, you like them very much and are very interested in them.
countable noun: A fan is a flat object that you hold in your hand and wave in order to move the air and make yourself feel cooler.
countable noun: A fan is a piece of electrical or mechanical equipment with blades that go round and round. It keeps a room or machine cool or gets rid of unpleasant smells.
countable noun: You can describe anything that has the shape of a wide ' V' with a curved part above it as a fan.
verb: If you fan yourself or your face when you are hot, you wave a fan or other flat object in order to make yourself feel cooler.

Fan in American English
noun

fan in American English 1
a device for winnowing grain
to move or agitate (air) with or as with a fan
to strike out
noun: any device for producing a current of air by the movement of a broad surface or a number of such surfaces

fan in American English 2
a person enthusiastic about a specified sport, pastime, or performer; devotee
noun: an enthusiastic devotee, follower, or admirer of a sport, pastime, celebrity, etc.

fan in Automotive Engineering
noun: A fan is a piece of electrical or mechanical equipment with blades that rotate. It is used to keep a machine cool or get rid of unpleasant smells.

fan in British English 1
noun: any device for creating a current of air by movement of a surface or number of surfaces, esp a rotating device consisting of a number of blades attached to a central hub
verb: to cause a current of air, esp cool air, to blow upon, as by means of a fan

fan in British English 2
noun: an ardent admirer of a pop star, film actor, football team, etc

fan in Chemical Engineering
noun: A fan is a device in which blades move around and make a free gas flow.

fan in Mechanical Engineering
noun: A fan is a device with spinning blades that create a flow of gas.