Difficult retreating in rich silk city (8)
I believe the answer is:
ticklish
'difficult' is the definition.
(similar in meaning)
'retreating in rich silk city' is the wordplay.
'retreating' says the letters should be written backwards.
'in' indicates the answer is hidden within the clue.
'hsilkcit' is hidden in the letters of 'rich silk city'.
'hsilkcit' written backwards gives 'TICKLISH'.
(Other definitions for ticklish that I've seen before include "easy to get to laugh?" , "Prone to responding to 1 across" , "Sensitive, needing delicate handling" , "Like a sensitive soul, so to speak" , "(Of a problem) difficult to handle and requiring great tact" .)