Thick (5)
'thick' is the definition.
(I know that thick can be written as dense)
This is the entire clue.
(Other definitions for dense that I've seen before include "Thick and tightly-packed" , "Needs (anag) -- thick" , "Close knit" , "Closely spaced or extremely stupid" , "Thick as undergrowth may be" .)
'thick' is the definition.
(I've seen this before)
This is all the clue.
(Other definitions for solid that I've seen before include "Firm - sound - reliable" , "Neither liquid nor gas" , "cone-shaped, say" , "Substantial - having three dimensions" , "Firm - three-dimensional" .)