| A few fries short of a Happy Meal | 33 |
| Sold-out show | 13 |
| Overgrown | 9 |
| Not too astute | 14 |
| Hard to get through to | 22 |
| None too smart | 14 |
| None too bright | 15 |
| Foggy | 5 |
| Thick-headed | 12 |
| Not the brightest bulb on the tree | 34 |
| Like some fog | 13 |
| Heavy, as fog | 13 |
| Hard to penetrate | 17 |
| Crammed | 7 |
| A few bricks shy of a load | 26 |
| Like some forests | 17 |
| Like a blockhead | 16 |
| Hard to see through | 19 |
| Cement-headed | 13 |
| Bubble-headed | 13 |
| Tough to get through to | 23 |
| Not the sharpest tool in the shed | 33 |
| No rocket scientist | 19 |
| Like heavy fog | 14 |
| Like a thicket | 14 |
| Dimwitted | 9 |
| Crowded together | 16 |
| Very thick | 10 |
| Tough to get through | 20 |
| Thick, as fog | 13 |
| Slow to understand | 18 |
| Slow to catch on | 16 |
| Serried | 7 |
| Opaque | 6 |
| Not too swift | 13 |
| Not sparse | 10 |
| Not Mensa material | 18 |
| Not at all sharp | 16 |
| None too swift | 14 |
| None too brainy | 15 |
| Like urban populations | 22 |
| Like a dumbbell | 15 |
| Like a copse | 12 |
| Highly concentrated | 19 |
| Hard to get through | 19 |
| Compacted | 9 |
| Closely packed | 14 |
| Closely crowded together | 24 |
| Blockheaded | 11 |
| Thick, like fog | 15 |
| Thick in a couple of ways | 25 |
| Thick headed | 12 |
| Short on sharpness | 18 |
| Scarcely bright | 15 |
| Rearranged needs? | 17 |
| Really crammed in | 17 |
| Practically impenetrable | 24 |
| Populous | 8 |
| Packed with ideas, as an essay | 30 |
| Packed tight | 12 |
| Packed in tight | 15 |
| Not very sharp | 14 |
| Not the sharpest pencil in the box | 34 |
| Not so swift on the uptake | 26 |
| Not getting it | 14 |
| None too quick on the uptake | 28 |
| Needs another way? | 18 |
| Meatheaded | 10 |
| Like thickets | 13 |
| Like thick audience | 19 |
| Like some populations | 21 |
| Like pea-soup fog | 17 |
| Like osmium, more than any other known element | 46 |
| Like Jupiter's atmosphere | 29 |
| Like dunderheads | 16 |
| Like depleted uranium | 21 |
| Like crowd at big show | 22 |
| Like Archie's pal Moose | 27 |
| Like a numbskull | 16 |
| Like a black hole | 17 |
| Incredibly thick | 16 |
| Heavy, like some baked goods | 28 |
| Having a high specific gravity | 30 |
| Hardly suited for Mensa | 23 |
| Hardly sparse | 13 |
| Hardly qualified to be a rocket scientist | 41 |
| Guolaugur Ottarsson: "___ Time" | 41 |
| Dumb as a box of rocks | 22 |
| Crowd at big show | 17 |
| Close-packed | 12 |
| Chuckleheaded | 13 |
| Blockish | 8 |
| A little on the slow side | 25 |
| A few bits short of a byte | 26 |
| Thick stick-in-the-mud? | 23 |
| Not as bright | 13 |
| Less clear | 10 |
| Thicker | 7 |
| More thickheaded | 16 |
| Not so sparse | 13 |