Driveway sealer (3)
I believe the answer is:
tar
'driveway sealer' is the definition.
(I've seen this in another clue)
This is the entire clue.
(Other definitions for tar that I've seen before include "Sailor and dressing for roads" , "It may cover the road" , "not put on ship in proverbial case of false economy?" , "Old salt or liquid from coal" , "Old salt, sailor" .)