Fraud bound to include City in retrospect (6)
I believe the answer is:
deceit
'fraud' is the definition.
(thesaurus)
'bound to include city in retrospect' is the wordplay.
'bound' becomes 'tied' (I've seen this before).
'to include' means one lot of letters goes inside another.
'city' becomes 'ec' (the City of London postcode).
'in retrospect' says the letters should be written backwards.
'tied' placed around 'ec' is 'tieced'.
'tieced' back-to-front is 'DECEIT'.
(Other definitions for deceit that I've seen before include "Subterfuge" , "Fraud, falsity" , "Dishonest trick" , "Cunning trickery" , "Lying" .)