What is Mfcsb?
1.
Motherfucking Cocksucking Bitch or Motherfucking Cocksucking Bastard.
Flat out one of the best ways to make fun of someone. It means exactly what it stands for.
Developed by myself.
Dude1: Yo, dude, it looks like u put some weight on!
Dude2: Bull shit, you MFCSB!
See 
Random Words:
1. 
Some one who is vertically chanllenged, very short, or petite
That girl is a rumple shroom skin cuz she's so damn short
See small.. 
1. 
The diction that only dumbass urban dictionary editors allow because they are far too unintelligent to support a valid attempt at spruci..