From the latin, "Radia Terra mestitori", Meaning, Literally, "I cover your land with my menstruation" an ancient roman curse.
"Oi, pickfucker! you want some radio-terra-mestitution? yeah?, fuckin' come on then?" (in the voice of a roman legionary, shouting at some less advanced guys who they're gonna kick the shit out of sometime soon. But they're going to bring money and toilets and technology with them, so it's not so bad really.
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.