KAON
Set to 2 different clues across 2 published puzzles, most often “Particle named for a letter of the alphabet” — The New York Times, Saturday, 26 September 2009.
4 letters
Every clue on record, most used first
- Particle named for a letter of the alphabetonce
The New York Times — Saturday, 26 September 2009
- Unstable subatomic particleonce
The New York Times — Sunday, 17 December 2006