CLACKS
Set to 2 different clues across 2 published puzzles, most often “Knocking sounds” — The New York Times, Thursday, 24 June 2004.
6 letters
Every clue on record, most used first
- Knocking soundsonce
The New York Times — Thursday, 24 June 2004
- Old telegraph machine soundsonce
The New York Times — Saturday, 8 July 2000