Binge drink around centre of London (6)
I believe the answer is:
bender
'binge' is the definition.
(synonyms)
'drink around centre of london' is the wordplay.
'drink' becomes 'beer' (beer is a kind of drink).
'around' is an insertion indicator.
'centre of' says to take the centre.
The centre of 'london' is 'nd'.
'beer' placed around 'nd' is 'BENDER'.
(Other definitions for bender that I've seen before include "Wild drinking spree" , "Drinking jag" , "Binge on drinks" , "Booze-up" , "makeshift shelter" .)