To piss very rapidly and for a great length of time. Often times the piss produces a strong piss shiver and the piss may be of an abnormal color. The shiver may make your balls tingle.
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.