It's when you put four fingers (2 on each hand) in a bitches ass while banging her, once filthy you remove and and insert two in her mouth and two up her nose. Finally finish it off with a side of ranch (jizzle) on her cheek
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.