Generally a fake looking woman with fake boobs/push up bra, thick layers of make-up, hair dyed some horrendous colour and are never seen without high heels.
They are usually seen twiddling their hair and uttering unintelligible sentences.
Boy: "That blonde over there used to be in my class...she's such a bimbo."
Girl: "Did she graduate in bimboism?"
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.