Polish husband spotted cops (5)
I believe the answer is:
sheen
'polish' is the definition.
(I've seen this before)
'husband spotted cops' is the wordplay.
'husband' becomes 'h'.
'spotted' becomes 'seen' (I've seen this in another clue).
'cops' indicates putting letters inside (inserted letters are caught or copped).
'h' put within 'seen' is 'SHEEN'.
(Other definitions for sheen that I've seen before include "Polish" , "Surface shine" , "Acting family" , "place in London" , "Superficial brightness" .)