Shart: To have the feeling of a fart, only to later find out after releasing the fart that it was actually poo.
Lucky Shart: This is when you shart during an important time, or place, such as school, your job, a business meeting, or a date.
Tommy is on a date with the girl of his dreams, when he feels a fart coming on, he then prepares to release it silently, and give the blame to the waiter. Despite his efforts, the fart was loud, and was infact a Lucky Sharts. he goes to change but is then left with embarressment, and the bill.