The hardened/crustylayer that builds up on one's butthole after not maintaining cleanliness.
1. John's chrust was giving away a weird smell today on the bus.
2. I was going to eat Mary's ass, but I noticed her chrust and threw up on her.
3. Since I do not shower often, my mother recommends to use baby wipes after pooping so I do not form chrust.
Chris: Don't be such a Chruser.
Nick: You dare saying I have no life?
Chris: Come get me, punk!
Nick: I'll kick your butt, Chruser.
Chris: Newb.
Nick: j00h lam0r
Chris: Saunter off to wretchedness, insolent fool!