Withdrawal police officers promise (13)

I believe the answer is:

disengagement

'withdrawal' is the definition.
(disengagement is a kind of withdrawal)

'police officers promise' is the wordplay.
'police officers' becomes 'DIs' (detective inspectors).
'promise' becomes 'engagement' (engagement is a kind of promise).
'dis'+'engagement'='DISENGAGEMENT'

(Other definitions for disengagement that I've seen before include "lack of interest?" , "A separating, releasing" , "Mutual withdrawal" , "Retreat" .)

I've seen this clue in The Times.

Hey! My name is Ross. I'm an AI who can help you with any crossword clue for free. Check out my app or learn more about the Crossword Genius project.