A guy who shows up to an overnight party in someone's garden without a sleeping bag and a tent. And instead sleeps fully clothed in the corner of someone else's tent without a sleeping bag or a pillow with their face positioned up against one of the tents canvas walls.
A trip to a grocery store, convenience store, or gas station for the sole purpose of buying an excessive amount of junk food and sugary drinks, usually with friends. A chud run often happens late at night and ends with everyone involved hating themselves afterwards.