usually used as a nickname to describe someone who in other words is a complete sex crazed weirdo who gets off on anything that has little or no sex appeal.
Friend: ooooooooh yeah that girl just looked at me.She's totally a slut.
Me: Dude what the fuck are talking about corndog;that girl is like those she males!
(note when conversation is going on corndog's boner is sticking out which makes it more awkward for him and you.)
A corndog is when you take your cock and shove it in a girls ass after she has diahrea, then let it hardened around your cock (1-2 hrs approx), then you fuck the girl with it.
She let me corndog, after hours of begging. What else would I do with my poop hardened cock? She shit all over it.