A frat injury. An injury, to a beastly frat
guy, that he suffers during a night of drinking. At the time of the Frinjury, you'
re like "
ow that hurts." You then keep crushing, and think nothing of it.
The next morning, however, when you wake up,
god help you. Not only are you in a lot of pain, but you remember the "spill" you took, or whatever caused the Frinjury. You'
re reaction is then "wow, that's why it feels like I shattered my knee cap," or "that bruise is the size of a country." (usually with the bruises, someone else notices, thus leading to a fratty interaction.)