The act of examining the physical damage to your underwear your recent shart has done mid-day. Effects may worsen if you have done this at a sleepover and left your underwear hanging around on accident, striking fear in your friends and foes' hearts.
Burt: "Woah, look at this sharterror. This thing is f*cking nasty!"
Mike: "That's not a sharterror, that's a mirror."
When the scene of a shart is left unattended over an extended period of time the sharticles, or particles of shart begin to harden due atmospheric exposure.
This results in the shart forming a thin crusty lining in the jocks which although uncomfortable, is sometimes preferable to admitting to having performed the initial shart in the first place.
"I knew I should have changed after that shart. Now I've got hardening of the sharteries."
"Madeline is walking a bit gingerly today, maybe she's got hardening of the sharteries..."
1. Like a hipster, but smellier...
2. Someone who takes as much pride in shitting themselves publicly as most hipsters do of their unique and ironic music collections.
3. See also: douchebag