Filed from 3 published puzzles

LAMEBRAIN

Set to 3 different clues across 3 published puzzles, most often “Knucklehead” — The New York Times, Wednesday, 16 June 2010.

9 letters

Every clue on record, most used first

Knuckleheadonce
The New York Times — Wednesday, 16 June 2010
Expert in ornamental fabrics?once
The New York Times — Sunday, 23 July 2006
Chuckleheadonce
The New York Times — Sunday, 1 April 2001

Other answers to these clues

ASS3 letters
BOOB4 letters
BOZO4 letters
CLOD4 letters
DODO4 letters
DOPE4 letters
DUNCE5 letters
IDIOT5 letters
IGNORAMUS9 letters
MORON5 letters
NITWIT6 letters
SAP3 letters