short for - My Anaconda Don't Want None.
pronounced Mah-Dohn (o as in don't; dwn like pwn)
used to express severely -not- wanting to have sex with a girl because she seems crazy, a bitch, or likely to be disease infested.
do. not. want.
especially when a girl does something off-putting or crazy in an attempt to arouse.
Bro: "Dude, that hot chick is looking at you"
Normal Guy: "which one?"
Bro: "the one with the glassy eyes that just stuffed her fist in her mouth and is slapping herself in the face."
Normal Guy: "oh, yuck. MADWN."
Bro: "mine does. i'm gonna go talk to her."