| 2026-08-30 | Like some liquors |
| 2026-08-20 | Firm |
| 2026-02-09 | Like sudokus with very few given digits, generally |
| 2025-04-30 | Like a 1,000-piece monochromatic jigsaw puzzle |
| 2025-04-14 | Like diamonds and calculus problems |
| 2023-10-26 | Word with copy or currency |
| 2022-12-24 | Forcefully |
| 2021-01-10 | Like Parmesan and pecorino |
| 2020-12-08 | Like a Saturday crossword |
| 2019-10-30 | Tough |
| 2019-07-12 | Like a rock and many a roll |
| 2019-03-27 | Like walnut shells |
| 2016-07-08 | With 60-Down, gotten by great effort |
| 2015-07-19 | Herculean |
| 2015-04-30 | Brain-busting |
| 2014-10-02 | Not squishy |
| 2012-06-28 | You might give this to someone you don't like |
| 2012-05-11 | Kind of rock or candy |
| 2011-05-05 | Fatiguing |
| 2010-01-24 | Brain-busting |
| 2009-04-28 | ___ as a diamond |
| 2008-04-21 | Difficult |
| 2008-03-17 | Rocklike |
| 2008-01-23 | Obdurate |
| 2007-09-08 | Compact |
| 2007-06-18 | Rocklike |
| 2007-06-04 | Steellike |
| 2006-12-31 | Not liquidy |
| 2005-04-07 | Like some cider |
| 2004-04-11 | Verifiable, as facts |
| 2003-04-01 | Knotty |
| 2001-10-29 | Brain-busting |
| 2001-07-16 | Arduous |
| 2001-07-03 | Granitelike |
| 2001-05-01 | Stony |
| 1998-09-14 | Brainbusting |
| 1998-05-08 | Like some candy |
| 1997-07-25 | Like a Friday crossword |
| 1997-01-12 | Like Hannah's heart, in song |
| 1996-10-04 | Herculean |
| 1995-05-14 | Like #4 pencils |
| 1995-03-29 | Difficult |
| 1994-10-05 | Rocky |
| 1994-10-04 | Difficult |
| 1994-03-02 | Granitelike |