Impenetrable (4)
'impenetrable' is the definition.
(I know that impenetrable can be written as dense)
This is the entire clue.
(Other definitions for dense that I've seen before include "Close knit" , "Thick, compact or crowded" , "Thick; stupid" , "Stupid; compacted" , "Closely packed" .)
'impenetrable' is the definition.
(similar in meaning)
This is the entire clue.
(Other definitions for opaque that I've seen before include "Hard to understand, see through" , "Not transparent, light can't pass through" , "Hazy, unclear" , "Not clearly expressed" , "Unintelligible" .)
'impenetrable' is the definition.
(thesaurus)
This is the entire clue.
(Other definitions for deep that I've seen before include "greatly involved?" , "dangerous for swimming?" , "hard to follow" , "Sunk low" , "Intense; low (in pitch)" .)