The term barnyard refers to a state of being, or an action, that is ridiculous, or wild like a farm animal, anything that could be related to being wasted and making a fool of yourself etc.
a moron who was likely raised in a barn or who attended school in the barn. someone who was so sub human that they had to live in the barn behind the farm because they were so filthy and retarded that they embarrassed their family.
a sick, really cool, awesome, radical, type thing. Barnyard is associated with awesome attitude, behavior, appearance and style. when you think of barnyard you think "wow, thats amazing."