Part of CIA (6)
I believe the answer is:
agency
'part of cia' is the definition.
(I've seen this in another clue)
This is the entire clue.
(Other definitions for agency that I've seen before include "Business that conducts business on behalf of another" , "Business that acts for other businesses" , "Business that works on behalf of another" , "Travel --; dating --" , "Organisation providing a particular service" .)