Different part of Rotherhithe (5)
I believe the answer is:
other
'different' is the definition.
(I've seen this before)
'part of rotherhithe' is the wordplay.
'part of' indicates a hidden word.
'OTHER' can be found hidden inside 'rotherhithe'.
(Other definitions for other that I've seen before include "Different, alternative" , "not like you" , "Different (from those mentioned)" , "Throe (anag)" , "Different; additional" .)