Used to describe a close minded person that will argue for the sake of arguing. They will take a stance against you regardless of the information presented, accuracy is not important. If proven wrong via facts, they will continue to argue and/or attempt to move the conversation to a different topic.
This Reddit user is a fence post. Move along and stop wasting your time.
In Female-to-Male (FTM) transsexuals, any type of penile prosthesis, especially those made of silicone that are made to extend and retract to simulate an erection in the by the owner's manipulation.
"Holy shit! Look at the bulge in her pants! I'm pretty sure she's packing a Wyoming Fence Post!"