To enrage or infuriate someone by not giving them or not granting them something they want or need. It is also done while utilizing condescention and mild sarcasm. It is usually done in such a manner that cannot be proven or come back on the person that is doing the Fat Handing.
The lady at the Public Works window had a bad day and decided to take it out on the next customer by Fat Handing him. She said in a very condescending manner, "Sir, I'm sorry but the forms you filled out in triplicate are incorrect because you used blue ink instead of black. You'll have to come back after my lunch hour and fill them out again. Have a nice day". She did this while staring at her finger nails.
This term will help those familiar with table football, or foos as it is more commonly know, to name a common injury. The injury occurs while rolling a rod up your wrist and forearm. It leads to red marks and eventual bruising and in some extreme cases can lead to your hand swelling up, thus fat hand.
'wow that hand looks swollen'
'yeah i got some serious fat hand dude'