IED

Set to 3 different clues across 3 published puzzles, most often “Roadside bomb, for short” — The New York Times, Tuesday, 5 April 2011.

3 letters

Every clue on record, most used first

Roadside bomb, for shortonce
The New York Times — Tuesday, 5 April 2011
Weapon for Iraqi insurgents: Abbr.once
The New York Times — Tuesday, 17 August 2010
Roadside bomb: Abbr.once
The New York Times — Sunday, 27 June 2010