One who is, or will be a person that does very stupid or dumb stuff, popularized in the movie 'Brokeback Barnabus'using its alternate definnition which refers to a homosexual mans tendency to perform gay sex acts, resulting in a 'shit dip.'
Example 1: Luke: "Gee, lets go pour milk on the snow! That'll really stick it to the man!"
Don: "Luke, you ar such a shit dip!"
Example 2: Barnabus: "Hey boys, you want to play?"
Phillip: "Barnabus, I'll shit dip with you any day!"