Use external company to expose spy's confidant (9)
I believe the answer is:
outsource
'use external company' is the definition.
I know nothing about this answer so I cannot tell whether it can be defined by this definition.
'expose spy's confidant' is the wordplay.
'expose' becomes 'out' (outing is a kind of exposing).
'spy's confidant' becomes 'source' (I am not sure about this - if you are sure you should believe this answer much more).
'out'+'source'='OUTSOURCE'
'to' acts as a link.
Can you help me to learn more?
(Other definitions for outsource that I've seen before include "Place (work) with external contractors" , "Avoid working oneself" , "Use contractors" , "Contract with external company" , "Subcontract work" .)