Intelligence calculates pi on a general sequence (9)
I believe the answer is:
espionage
'intelligence' is the definition.
(I know that espionage is a type of spying)
'calculates pi on a general sequence' is the wordplay.
'ESPIONAGE' is hidden in amongst the letters.
However, I'm not sure how this is indicated.
Can you help me to learn more?
(Other definitions for espionage that I've seen before include "agent's job" , "hush-hush work" , "Practice of spying" , "secret work" , "undercover work" .)