A word usually used to describe an obese female who is Particularly blonde in nature. Some fatney's can be easily spotted on the internet, making big mac collages, or even having a skype convo with you claiming that when its time for her to log off - That 'she is going to the club to get drunk'. However- there is a 99% chance, that she is really talking about mcdonalds, and is planning on abusing the soft drink stand.
Krikey! A fatney just ate my baby.