To have too much caffeine in your system to a point where you can no longer have proper train of thought.
Jim : "I guesstimated that!"
Karl : "what's guesstimation dude?"
Jim : "It's like guessing and estimating.......I don't know im really caffinated right now!"
Karl : "Take 5 Jim!"
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.