Historical clue formulations

• Chicken — 2026-06-11
• Yellow, so to speak — 2023-04-06
• Chicken ... or cowed — 2022-02-27
• Shaking in one's boots — 2021-09-15
• Lily-livered — 2017-10-05
• Trembling, say — 2017-07-09
• Terror-stricken — 2016-06-21
• Yellow — 2014-01-17
• Lily-livered — 2012-03-08
• Craven — 2009-05-24
• Not stout — 2007-06-29
• Yellow — 2005-01-02
• Yellow — 1997-01-16