Cautious, circumspect (8)
I believe the answer is:
discreet
I believe this is a double definition.
'cautious' is the first definition.
(thesaurus)
'circumspect' is the second definition.
(I know that circumspect can be written as discreet)
(Other definitions for discreet that I've seen before include "Careful not to attract attention" , "Diplomatic" , "Cautious, not giving away secrets" , "Showing prudence and circumspection" , "Unobtrusive, circumspect" .)