A wedge is often used as a tool to stop objects from moving, it is a primitive tool that is not very useful in other scenarios. It can also be used as an insult to call someone useless or dumb.
Man this guy is a fucking wedge
A Wedge is often used to stop a door, it is a very primitive tool that is not very useful with other things. Therefore it can be used as an insult
Man this guy is a fucking wedge