Bow Road Tube station (7)
I believe the answer is:
archway
'tube station' is the definition.
The answer and definition can be both man-made objects as well as being singular nouns.
Perhaps there's a link between them I don't understand?
'bow road' is the wordplay.
'bow' becomes 'arch' (both can mean to curve).
'road' becomes 'way' (I've seen this in other clues).
'arch'+'way'='ARCHWAY'
Can you help me to learn more?
(Other definitions for archway that I've seen before include "entrance, perhaps" , "Curved entrance" , "part of London" , "Vaulted passage" , "Entrance structure" .)