Like a dungeon (4)
I believe the answer is:
dank
'like a dungeon' is the definition.
(I've seen this in another clue)
This is the entire clue.
(Other definitions for dank that I've seen before include "Chilly and clammy" , "Clammy, damp" , "Cold and moist" , "Damp, cold, musty" , "Unpleasantly cold and humid" .)