Thick liquid, distilled from coal (3)
I believe the answer is:
tar
'thick liquid distilled from coal' is the definition.
(I've seen this before)
This is the entire clue.
(Other definitions for tar that I've seen before include "Thick, sticky liquid distilled from coal" , "Sailor - laid on road" , "It paves the way" , "One sails on sea" , "Black substance in cigarettes" .)