The teacher instructed the class to not begin writing the test until she has indicated that it is okay to start. "Give 'er beans!" she said, indicating that it was now indeed time to begin the test.
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.