empty set 

1.The empty set is not the same thing as nothing; it is a set with nothing inside it. It's a mathmatical term.
2. The head of a stupid person.

Kevin is such an empty set. He's got nothing going on upstairs.

empty set by Sandi68 April 28, 2006

Empty Set of Loafers 

In middle management a person who thinks that they know what they are doing but in reality they have no clue of what is actually going on.

That guy thinks that he knows what he is doing but he is an empty set of Loafers.

Empty Set of Loafers by Coop1964 October 30, 2015