Historical clue formulations

• Giggle — 2024-07-21
• Half-laugh — 2019-07-18
• Nervous giggle — 2014-03-12
• Nervous laugh — 2010-12-30
• Nervous laugh — 2009-10-15
• Nervous giggle — 2007-03-05
• Nervous laugh — 2004-06-02
• Tee-hee — 2000-12-17
• Self-conscious laugh — 1998-04-19