The document describes an activity where a character named George goes through different idioms and their definitions. For each idiom, the user selects the correct definition from multiple choice options. Some of the idioms explained include "raining cats and dogs" which means to rain very heavily, "let the cat out of the bag" which means to tell something that is supposed to be a secret, and "open a can of worms" which means to do something that will cause problems. The purpose is to learn common idioms and their contextual meanings.