The almost non-existent region of a caucasion male or female located beneath the after portion of his or her mid section.
Johnny: "Did you see the butt on that girl at the tractor pull on Firday?"
Dale: "Sure didn't!"
Johnny: "What about you, Ben?"
Stephanie: "That's because she had a gluteus whitius. It's nothin' like my big ol' bahonkydunk