Attack a doctor in city street (7)
I believe the answer is:
lambast
'attack' is the definition.
'a doctor in city street' is the wordplay.
'doctor' becomes 'mb' (Bachelor of Medicine, Medicinae Baccalaureus**).
'in' means one lot of letters goes inside another.
'city' becomes 'la' (Los Angeles).
'street' becomes 'st'.
'a'+'mb'='amb'
'amb' going within 'la' is 'lamba'.
'lamba'+'st'='LAMBAST'
(Other definitions for lambast that I've seen before include "Criticise severely" , "Harshly criticise" , "Berate" , "Bash" , "rubbish" .)