The term Dunhill fowl has been around since before the 1800's and for the most part referred to a chicken that would not fight.Chris,
I disagree with that as the only criteria. My grandma (born in 1893, died in 1991) referred to chickens that roamed around and scratched in the manure piles as dunghill fowl. She never raised Gamefowl. I personally feel it is a general term applied to common yard chickens as well.
Chris