Filed from 3 published puzzles

HARHAR

Set to 3 different clues across 3 published puzzles, most often “Sarcastic laugh” — The New York Times, Thursday, 26 June 2008.

6 letters

Every clue on record, most used first

Sarcastic laughonce
The New York Times — Thursday, 26 June 2008
"Very funny"once
The New York Times — Friday, 20 September 2002
Sound of feigned laughteronce
The New York Times — Sunday, 19 September 1999

Other answers to these clues

HAHA4 letters
HAHAHA6 letters