Term used during WLC(warrior leadership course) in the ARMY when a fellow battle buddy switches MRE's(meal ready to eat) when you are taking a piss. You come back to find out your mcrib sandwich was replaced with a vegetable omelet MRE resulting in you calling him a cock omelet out of frustration and disappointment to finding out that you have the worse possible MRE in the face of the earth. Can be used in any situation resulting in where a person is a cock omelet.
"Dave, what are you giggling about?"
"WTF!!!! veggie omelet????? what happened to my mc rib MRE?!?!?"
"you fucking cock omelet!!"