CIA spy crept around gathering international intelligence (12)
I believe the answer is:
perspicacity
'intelligence' is the definition.
(I know that perspicacity is a type of intelligence)
'cia spy crept around gathering international' is the wordplay.
'around' is an anagram indicator.
'gathering' indicates putting letters inside.
'international' becomes 'i' (abbreviation eg in IMF).
'cia'+'spy'+'crept'='ciaspycrept'
'ciaspycrept' anagrammed gives 'perspcacity'.
'perspcacity' enclosing 'i' is 'PERSPICACITY'.
(Other definitions for perspicacity that I've seen before include "Astute intelligence" , "Insight into and understanding of things" , "Clear-mindedness - crappy cities (anag)" , "Insight, perception" .)