Furtive, duplicitous (6)
I believe the answer is:
shifty
I believe this is a double definition.
'furtive' is the first definition.
(I've seen this in another clue)
'duplicitous' is the second definition.
(thesaurus)
(Other definitions for shifty that I've seen before include "Suspicious-looking" , "Sly, shady" , "Shady, dubious" , "Constantly changing; deceitful, evasive" , "Devious - wily" .)