Mugging of bishop wearing vestment on railway (7)
I believe the answer is:
robbery
'mugging' is the definition.
(I know that mugging can be written as robbery)
'bishop wearing vestment on railway' is the wordplay.
'bishop' becomes 'B' (chess abbreviation).
'wearing' means one lot of letters goes inside another.
'vestment' becomes 'robe' (I've seen this in another clue).
'on' means one lot of letters go next to another.
'railway' becomes 'ry' (abbreviation).
'b' inserted inside 'robe' is 'robbe'.
'robbe'+'ry'='ROBBERY'
'of' is the link.
(Other definitions for robbery that I've seen before include "Theft, stealing" , "Theft of property" , "Theft crime" , "Theft maybe with violence" , "Criminal action" .)