This is a word that people use when they are really stupid and can't say "big-boy big girl" words. Whenever you hear someone use the phrase "anti gay" correct them by saying "the word is homophobic biatch. Now really dumb people will argue that that is wrong and that it means that someone is afraid of gay people but if they would read the second definition they would know.
Oh my gosh he's anti gay? No stupid, he is homophobic!