Satirical magazine (7,3)
I believe the answer is:
private eye
'satirical magazine' is the definition.
(I know that Private Eye is a satirical magazine)
This is the entire clue.
(Other definitions for private eye that I've seen before include "50 today" , "Freelance detective" , "Satirical magazine - undercover detective" , "Spade, say" , "supplement to work of police?" .)