Paving goop (3)
I believe the answer is:
tar
'paving goop' 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 "Black liquid from coal" , "Liquid from wood, coal" , "Informal sailor or coal distillation" , "Black substance, used on roads" , "Dark flammable liquid" .)