CIA worry (4)
I believe the answer is:
mole
'cia worry' is the definition.
(I've seen this in another clue)
This is the entire clue.
(Other definitions for mole that I've seen before include "Spy - one that burrows" , "Spy; blemish" , "Heap of soil (a 6 mountain?)" , "Small congenital skin spot" , "Spy - creator of hills?" .)