Still or inactive (8)
I believe the answer is:
stagnant
I believe this clue is a double definition.
'still' is the first definition.
(synonyms)
'inactive' is the second definition.
(I've seen this in another clue)
(Other definitions for stagnant that I've seen before include "(Water) not flowing" , "Showing little activity" , "(Of water) motionless" , "Brackish and foul" , "Still and foul" .)