From Longman Dictionary of Contemporary Englishdoorknockerdoor‧knock‧er /ˈdɔːˌnɒkə $ ˈdɔːrˌnɑːkər/ (also knocker) noun [countable] DHHa heavy metal ring or bar on a door that you use to knock with
Examples from the Corpus
doorknocker• On it were a variety of jugs and china vases from the same school of design as the pixie doorknocker. 