Clothes line in high road to palace (3,4)
I believe the answer is:
the mall
'road to palace' is the definition.
I can't judge whether this definition defines the answer.
'clothes line in high' is the wordplay.
'clothes line' becomes 'hem' (I've seen this in another clue).
'in' indicates putting letters inside.
'high' becomes 'tall' (associated in meaning).
'hem' inserted inside 'tall' is 'THE MALL'.
(Other definitions for the mall that I've seen before include "Route to Buckingham Palace" , "way in London" .)