| 2026-07-29 | Packed in |
| 2026-01-24 | Like tungsten |
| 2025-10-19 | Tightly packed |
| 2025-08-25 | Slow on the uptake |
| 2025-05-20 | Like pound cake |
| 2025-03-10 | Thick |
| 2024-03-14 | Like lead or gold, notably |
| 2023-10-19 | Mentally slow |
| 2023-09-03 | Slow to catch on |
| 2023-08-27 | Like flourless cake |
| 2023-08-21 | Opposite of sparse |
| 2023-03-24 | Like the element osmium |
| 2023-02-09 | Like a neutron star |
| 2022-12-21 | Like flourless cake |
| 2022-11-27 | Like dumbbells |
| 2022-11-15 | Slow on the uptake |
| 2021-11-23 | Tightly packed |
| 2021-07-23 | Junglelike |
| 2021-02-25 | Impenetrable |
| 2020-11-13 | Like some forests and fog |
| 2020-09-29 | Tightly packed |
| 2019-09-09 | Thickheaded |
| 2018-03-30 | Stupid |
| 2017-04-12 | Not too quick on the uptake |
| 2017-01-02 | Not the brightest bulb on the Christmas tree |
| 2016-06-19 | Blockheaded |
| 2016-01-31 | Unable to get it, say |
| 2016-01-06 | Slow on the uptake |
| 2015-01-11 | Like a neutron star |
| 2014-12-16 | Thickheaded |
| 2014-09-17 | Dumb as a box of rocks |
| 2013-08-24 | Not at all sharp |
| 2012-11-08 | Like a copse |
| 2012-09-30 | Like dunderheads |
| 2012-07-27 | Not getting it |
| 2011-10-20 | Packed with ideas, as an essay |
| 2011-10-15 | Like depleted uranium |
| 2011-08-14 | Like a black hole |
| 2011-04-20 | Slow on the uptake |
| 2010-12-29 | None too swift |
| 2008-10-03 | Not very sharp |
| 2008-08-12 | Not the sharpest pencil in the box |
| 2008-02-07 | Obtuse |
| 2008-01-13 | None too bright |
| 2007-02-22 | Packed |
| 2006-06-16 | Concentrated |
| 2006-05-08 | Thick |
| 2005-02-23 | Hardly suited for Mensa |
| 2004-05-30 | Doltish |
| 2004-02-29 | Like osmium, more than any other known element |
| 2004-01-24 | Packed |
| 2003-10-30 | Slow on the uptake |
| 2003-09-24 | Thickheaded |
| 2003-08-03 | Blockheaded |
| 2003-07-25 | Short on sharpness |
| 2002-09-28 | Unintelligent |
| 2002-01-24 | Doltish |
| 2001-07-31 | Not the brightest bulb on the tree |
| 2000-10-17 | Thickheaded |
| 2000-07-01 | Blockish |
| 1999-06-18 | Packed tight |
| 1999-04-05 | Crowded |
| 1998-12-27 | Not too swift |
| 1998-10-12 | Impenetrable |
| 1998-08-30 | None too brainy |
| 1998-07-01 | None too brainy |
| 1998-01-20 | Thickheaded |
| 1997-12-15 | Thick |
| 1997-10-22 | None too bright |
| 1996-10-19 | Not very swift |
| 1996-04-29 | Thick |
| 1996-01-28 | Compact |
| 1995-10-24 | Tightly packed |
| 1995-03-13 | Crowded |
| 1994-06-26 | Impenetrable |
| 1994-06-22 | Stupid |
| 1994-02-14 | Slow on the uptake |