A person who can never admit to being wrong and uses poor and unnecessarily complicated logic in an attempt to wear down the other person's patience in a discussion. Even after being proven wrong, they are too stubborn to admit defeat and continue to further complicate the issue and derail the point that was trying to be made in the first place, and ending up on a totally different tangent. These morons are easily thwarted by intelligent people who use simplicity in all their arguments to prove a point, which was made complicated by a Deem.
When I showed that Deem how he was wrong about how a jet engine works, he continued to argue excessively, eventually describing his experience in editing videos and how he was better at it because he did it more than everyone else. What was the initial point again? Don't ask the Deem!