The Shibboleth of Fëanor is the eleventh chapter of The Peoples of Middle-earth, which is the twelfth and most recently compiled volume of The History of Middle-earth. "Shibboleth" is a rare word defined as a custom, principle, or belief distinguishing a particular class or group of people, esp. a long-standing one regarded as outmoded or no longer important. The chapter that follows is "The Problem of Ros".