1. A polite way of saying Bull Shit, often times heard in Southern culture.
2.When someone says something untrue and you vehemently object to their false remark without cursing, you can say: "Bull Butter!"
3. An obvious lie.
Stan: "One time, I jumped out of a tree stand 20 ft up onto the back of a deer and I road it a mile before stabbing the deer with my pocket knife."
Chris: "Bull Butter!"