Originally used to describe a certain tribe of wild individuals found in Kentucky mountain regions. Daniel Boone once described them as a race of wild hairy giants, well known for bad behavior and violent or fiendish actions against early pioneer settlers. Term now often used to describe an individual who displays bad or antisocial behavior.
"When the player threw the ball at the referee, he was acting like a Yayhoo."
by BFRP February 09, 2010