Surface, as a road (4)
I believe the answer is:
pave
'surface as a road' is the definition.
(I've seen this in another clue)
This is all the clue.
(Other definitions for pave that I've seen before include "Cover with slabs" , "Surface with stone etc." , "Put on a surface of stone slabs" , "Dress with stone etc" , "Cover with flags" .)