Work of intelligence (6)
I believe the answer is:
spying
This might be a double definition.
'work' is the first definition.
The answer and definition can be both acts as well as being singular nouns.
Perhaps you can see a link between them that I don't see?
'intelligence' is the second definition.
(I know that spying is a type of intelligence)
'of' is the link.
Can you help me to learn more?
(Other definitions for spying that I've seen before include "Acting as a secret agent" , "Catching sight of; agent's job" , "collection of information" , "Activity undertaken by Blunt and Philby" , "Engaging in espionage" .)