ISINGLASS

Set to 2 different clues across 2 published puzzles, most often “Common mica” — The New York Times, Friday, 8 May 2009.

9 letters

Every clue on record, most used first

Common micaonce
The New York Times — Friday, 8 May 2009
Clarifying agent in glues and jelliesonce
The New York Times — Saturday, 21 August 1999