An undefinable girl and in some strange cases a guy. Madi's are not easy to find. If you ever meet a Madi you should immediatley go into the fetal position and hope to god the true fantasticness of this girl (boy sometimes) will shine down on you like the rays of the sun.
Frank: Hey what happened to you yesterday?
Bill: I saw a Madi.
Frank: and you didnt show up to be the best man at my wedding cause you saw a Madi?
Bill: Yes exactly
Frank: Thats horrible I don't understand how all you did yesterday was stare at a girl.
Bill: You have obviously never seen one before...