Bound to misfire as a ruse! (4)
I believe the answer is:
sure
'bound to' is the definition.
(synonyms)
'misfire as a ruse' is the wordplay.
'ruse' anagrams to 'SURE'.
However, I'm not sure how this is indicated.
Can you help me to learn more?
(Other definitions for sure that I've seen before include "The old sewer" , "of course" , "Confident sort of ruse" , "Certain to be a ruse" , "Agreed" .)