Open deception (5)
I believe the answer is:
bluff
I believe this clue is a double definition.
'open' is the first definition.
(thesaurus)
'deception' is the second definition.
(bluff is a kind of deception)
(Other definitions for bluff that I've seen before include "Challengers may call it" , "Hoodwink" , "Deceive by concealing weakness" , "Honest" , "Try to fool in poker game" .)