Cunt.
The United States Air Force flightcap resembles the labia when viewed from the top or turned on end and has been called the "C" cap or cunt cap for years. Flightcap has become code for cunt cap and is a more subtle way of calling a person (usually female) a cunt.
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.