Related Clues:
- Slow-witted duke seen dancing
- Thick section in garden seat
- Old penny dreadful seen as impenetrable
- Not too bright, duke seen wandering
- Crowded or tightly packed
- Highly populous
- Closely clustered
- Studies top of exquisite compact
- Like flourless cakes
- Stupid duke seen off
- Needs (anag) — thick
- Thick, in more ways than one
- ''Infinite'' descriptor of black holes
- Crowded or compact
- Like lush forests