a euphemism for defecation, used in conjunction with 'little-boy' (i.e. urination). Commonly used as a noun, but acceptable in verb form.
I shouldn't have had that seventh enchilada. I've never had to take a fat-man so bad in my life.
I always fat-man before i go to work in the morning.
I always fat-man before i go to work in the morning.
by Anonymous April 19, 2003

Tim: Joe doesn’t want to drive but will say yes to going if Isaac drives
Isaac: Aw shucks that mofo is fat!
Isaac: Aw shucks that mofo is fat!
by Johnymaddawg January 31, 2019

The Art Of Clapping 3 Times Then Hitting Ones Neck As Fast As Possible Inflicting The Most Pain Possible To The Back Of The Neck
by HighIQWords October 13, 2018

by cassandra claire February 20, 2019

by Not a heather January 16, 2022

by jeyooo October 16, 2017
