doornail

/ˈdɔrˌneɪl/
noun
  1. A large-headed nail once used to decorate or strengthen doors.
    • He ran his fingers over the cold, round head of a doornail.
    • The old oak door was studded with iron doornails.
    • The blacksmith forged a set of doornails for the castle gate.
  2. Used in the idiom 'dead as a doornail' to mean completely dead or lifeless.
    • By the time the vet arrived, the hamster was dead as a doornail.
    • The car engine sputtered once and then was dead as a doornail.
    • After the long winter, the old oak tree in the yard was dead as a doornail.