ANSWER
Set to 12 different clues across 13 published puzzles, most often “Echo” — The New York Times, Wednesday, 2 September 2009.
6 letters
Every clue on record, most used first
- Echo2 times
The New York Times — Wednesday, 2 September 2009
- Respond to a knockonce
The New York Times — Wednesday, 28 July 2010
- Come backonce
The New York Times — Friday, 2 June 2006
- "Jeopardy!" offeringonce
The New York Times — Sunday, 3 October 2004
- "Is that your final ___?"once
The New York Times — Monday, 16 April 2001
- Make a comebackonce
The New York Times — Friday, 8 December 2000
- Match, as a descriptiononce
The New York Times — Friday, 25 February 2000
- Echo, e.g.once
The New York Times — Tuesday, 20 October 1998
- Responseonce
The New York Times — Monday, 22 April 1996
- Replyonce
The New York Times — Monday, 10 July 1995
- Comebackonce
The New York Times — Sunday, 4 December 1994
- It will be printed tomorrowonce
The New York Times — Monday, 13 December 1993