Sly and secretive (7)
I believe the answer is:
furtive
'sly and secretive' is the definition.
(I've seen this before)
This is all the clue.
(Other definitions for furtive that I've seen before include "Surreptitious" , "Sly and secretive" , "Sly, underhand" , "Clandestine" , "Sneaky" .)