What Detective Chief Superintendent typically did to get rank (6)
I believe the answer is:
rancid
'rank' is the definition.
(I've seen this before)
I don't understand the remainder of the clue.
Can you help me to learn more?
(Other definitions for rancid that I've seen before include "(Of fats) stale" , "Smelly and going bad" , "Foul-tasting" , "Sour like stale fat" , "Sour like stale grease 96)" .)