Somebody who is SO homophobic that he cannot see straight and who furthermore cannot stop thinking about gays. He is so repelled/attracted on the subject that it affects his phallus and causes it to rise while his fellows tend to think he is a horse's ass
I have a friend named Shane who constantly talks about the gay community. He is always putting down them and their lifestyle. He inserts the topic into any discussion about anything. I have decided that he is clearly a homoerectum.