Haroon's like warm climates and are known to raise the temperature by at most 10 degrees (F) when they walk outside.
The term originated from Haroon Khan, a fat kid who was unable to get the time of day from a girl named Malaika whom he met over Facebook and made him horny. He then went on to make another account with the picture of someone else, and started having Facebook sex with her, ie. Jacking off while having dirty conversations in Facebook chat.
That muscular guy you were talking dirty with over Facebook wasn't who you thought it was ... you got haroon'd, Eman!
dude 2: ya she was hanging out with the hot foriegner
dude 1: didnt u kiss some other girl though?
dude 2: ya....
dude 1: wtf, your such a haroon