ALKENE
Set to 3 different clues across 3 published puzzles, most often “C2H4, e.g.” — The New York Times, Sunday, 14 October 2007.
6 letters
Every clue on record, most used first
- C2H4, e.g.once
The New York Times — Sunday, 14 October 2007
- Certain hydrocarbononce
The New York Times — Monday, 11 October 1999
- C4H8, e.g.once
The New York Times — Sunday, 8 June 1997