a pon fal
to make a mistake so big it could be entered into the world record books for stupidity
I a pon fal in my history exam and wrote 'George Washington was a pizza' instead of 'a president.'
I tried to do a magic trick and a pon fal so bad the whole school laughed for a full minute.
I a pon fal during a spelling bee and said 'caterpillar' instead of 'cataract.'