Historical clue formulations

• Like an angle between 90° and 180° — 2024-04-01
• More than 90° — 2023-08-28
• More than right — 2022-04-20
• Thickheaded — 2021-01-01
• Thickheaded — 2019-03-31
• Dense — 2016-01-16
• Slow to catch on — 2011-07-18
• Not sharp — 2009-07-03
• Thick — 2009-02-13
• Dense — 2007-12-06
• Not exactly insightful — 2007-12-04
• Slow on the uptake — 2006-07-13
• Dull — 2006-03-23
• Blunt — 2003-03-22
• More than 90° — 2001-12-17
• Hardly brainy — 1998-11-24
• Far from sharp — 1997-03-14
• Slow-witted — 1996-08-31