Related Clues:
- With a high mass-to-volume ratio
- Dumb as a rock
- Gather behind strike leader, flummoxed
- Like crowd during sold-out concert
- Not too quick on the uptake
- Tightly compressed
- Compact and tight together
- Really thick
- Like mercury
- Like pound cake
- Very compact
- Heavy, as a fog
- Closely spaced poles in river
- In an impossible situation
- Like platinum