knocking

koputus (present participle of)
An act in which something is knocked on, or the sound thus produced
{{quote-book|year=1893|author=W. B. Yeats|title=The Celtic Twilight|chapter=|edition=|url=http://www.gutenberg.org/etext/10459
{{quote-book|year=1901|author=Carson Jay Lee|title=Oswald Langdon|chapter=|edition=|url=http://www.gutenberg.org/etext/22221
{{quote-journal|date=July 21, 2006|author=Keith Harris, Monica Kendrick, Peter Margasak, Bob Mehr, Miles Raymer, Neil Tesser|title=The Treatment|work=Chicago Reader|url=https://securesite.chireader.com/cgi-bin/Archive/abridged2.bat?path=2006/060721/TREATMNT