Very hard getting round London district (4)
I believe the answer is:
'london district' is the definition.
(I've seen this before)
'very hard getting round' is the wordplay.
'very' becomes 'so' (I've seen this in other clues).
'hard' becomes 'h'.
'getting round' becomes 'o' (I've seen this in other clues).
'so'+'h'+'o'='SOHO'
(Other definitions for soho that I've seen before include "Hunter's announcement of sighting a hare" , "Colourful show-biz area of West End London" , "Entertainment district in London's West End" , "W London area" , "Nightclub area in London" .)