Filed from 3 published puzzles

REALEST

Set to 3 different clues across 3 published puzzles, most often “Least fictional” — The New York Times, Wednesday, 10 May 2006.

7 letters

Every clue on record, most used first

Least fictionalonce
The New York Times — Wednesday, 10 May 2006
Superlatively sincereonce
The New York Times — Friday, 9 March 2001
Most heartfeltonce
The New York Times — Wednesday, 11 November 1998