N. An occurrence in which one is essentially struck dumb by the revelation or comprehension of a previosuly-unknown fact. Misspelling of the common word "enlightening" is here intentional.
Generally used in the form "struck by enlightning."
See Also: TMI
Hearing that the world was not, in fact, flat, proved enlightning to Elena's delicate mind.
When Roy found out that his best friend from youth, who he'd always trusted, had been spying on him in the locker room due to being secretly gay, he was struck by enlightning and had no idea what to do.