Fat End First - inserting the fat end of something into a bodily cavity. This is usually with the intent to cause pain. Anything with a fat end and a slender end can be used in this manner: carrots,
baseball bats, and
water bottles to name a few. Depending on the bodily cavity selected, this
may result in difficulty in extracting the object. This acronym is generally used as a verb to describe the action of the penetration.