Origins are likely unknown - I'd assume Allentown, but I'm really doubtful of that. I heard it from this kid at a show in Cleveland, and just thought it so bizzare, I had to include it.
An Allentown Crabapple is just another word for penis, or rockhard errection.
"I'm gonna break her off some ol' allentown crabapple."
7👍 8👎