Gomer is a noun that refers to a stupid colleague. 

The precise origin of our word of the day is something of a mystery. There is a man named Gomer in the Bible, but some believe that the name became an insult after it was used on the character Gomer Pyle, the inept soldier depicted in the popular 1960s sitcom of the same name.

Regardless of its source, Gomer has become an unflattering term for somebody not very good at his job. Here’s an example:
At the ice cream stand, I developed a reputation as a Gomer after I made a few mistakes. But honestly, I didn’t feel I was that incompetent. Anybody can mistake a five-pound order for a five-gallon order, can’t they?