Well, there is in psychoanalytic theory -- it's the thing that people refer to as 'the self'. You might not *like* psychoanalytic theory, I don't much myself, but that's not the point. People (apart from you, it seems) know what you're talking about when you talk about ego.
It's simply a shorthand way of saying "I had the experience that I no longer existed as a seperate entity from the rest of the universe." This isn't an obscure thing that people don't understand. Look, here's Bill Hicks. Everybody posts this clip because anyone who's taken significant quantities of acid knows what he's talking about here. He's describing ego death.