COSTELLO

Set to 2 different clues across 2 published puzzles, most often "Who's on first?" asker — The New York Times, Wednesday, 13 June 2007.

8 letters

Every clue on record, most used first

"Who's on first?" askeronce
The New York Times — Wednesday, 13 June 2007
Half of a 1940's-50's comedy duoonce
The New York Times — Monday, 21 October 2002