B-Down
A person or thing so dumb it could make a donkey cry. Like the dumbest version of a donkey.
My cousin is a B-Down. He thought a chicken was a bird and a cow was a chicken.
My math teacher is a B-Down. He said 2+2=5 and I believed him for a week.
My dog is a B-Down. He barked at a cloud and it screamed back.