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