HALFLIFE
Set to 2 different clues across 2 published puzzles, most often “*Physics period” — The New York Times, Thursday, 8 October 2009.
8 letters
Every clue on record, most used first
- *Physics periodonce
The New York Times — Thursday, 8 October 2009
- Radioactive decay measureonce
The New York Times — Monday, 22 April 2002