Catch bluebottle (3)
I believe the answer is:
cop
This clue is a double definition.
'catch' is the first definition.
(cop can mean to arrest or apprehend)
'bluebottle' is the second definition.
(bluebottle can mean a police officer)
(Other definitions for cop that I've seen before include "Get" , "Policeman (sl)" , "An American policeman" , "busy" , "catch" .)