Bishop seen in gown has line in crime (7)
I believe the answer is:
robbery
'crime' is the definition.
(robbery is a kind of crime)
'bishop seen in gown has line' is the wordplay.
'bishop' becomes 'B' (chess abbreviation).
'seen in' indicates putting letters inside.
'gown' becomes 'robe' (synonyms).
'has' says to put letters next to each other.
'line' becomes 'ry' (abbreviation for railway).
'b' going within 'robe' is 'robbe'.
'robbe'+'ry'='ROBBERY'
'in' acts as a link.
(Other definitions for robbery that I've seen before include "Theft of property" , "Theft maybe with violence" , "Theft crime" , "Theft, stealing" , "Criminal action" .)