The document defines several idiomatic phrases: - To pay through the nose means to pay a lot of money. - To be a big cheese means to be an arrogant person in a position of power or importance. - To be a bookworm refers to someone who reads a lot. - To buy something for a song means to purchase it for a very low price. - To blow the whistle means to report illegal or unethical practices. - To call the tune means to be in control or give commands to others.