Missing a road (4)
I believe the answer is:
away
'missing' is the definition.
(I've seen this in another clue)
'a road' is the wordplay.
'road' becomes 'way' (I've seen this in other clues).
'a'+'way'='AWAY'
(Other definitions for away that I've seen before include "SECOND PART OF 18" , "Playing at the opponents' ground" , "At a distance; match" , "Game played at opponents' ground" , "Location of match played on opponent's ground" .)