Possible Clues:

• Old-fashioned 'as if!'
• Expression used to express disbelief
• 'It is to laugh!'
• Expression of contempt or impatience
• "Fiddlesticks"
• Play quietly before dramatist gives expression of contempt
• Scoffing exclamation
• Contempt for mum kept in hand
• ''Fiddle-de-dee!''
• Cousin of 'harrumph'