It's a portmanteau name that leftists sometimes use to refer to the President.
"Chimpy" because they claim he resembles a chimpanzee in either face or mind, "Bushit" is how they refer to anything he says, "Bushitler" is the phrase they use to compare him to Hitler and "Hitlerburton" is the way they refer to a large multinational company that he is allegedly to have close dealings with.
So, the handy name "Chimpy Bushitlerburton" compacts all their paranoid fantasies into one simple package.
*impeached