A shredder is a machine that cuts paper into thin strips or tiny bits so no one can read what was on it. Offices keep one for letters, bills, and anything with names or account numbers. Some take cards or whole folders; the everyday one is the paper machine on a desk or in a copy room. Factories also have shredders for wood, plastic, or food, and sports slang can call a fast snowboarder or guitar player a shredder — same building-block shred, different joke. In ordinary English this word is the document machine.