door knocker

A metal fixture mounted on the outside of a door that people use to announce their presence by knocking. It usually consists of a hinged piece (often shaped like a ring, hammer, or decorative figure) that you lift and let fall against a metal plate or the door itself to create a knocking sound. Door knockers have been used for centuries and often serve as decorative elements as well as functional ones.

See also

• doorbell
• peephole