Cigar residue (5)
I believe the answer is:
ashes
'cigar residue' is the definition.
(I've seen this in another clue)
This is the entire clue.
(Other definitions for ashes that I've seen before include "Powders remaining after fire" , "Remnants of a fire" , "Eng/Aus test series" , "Remains of the Yule logs?" , "''... to ..., dust to dust'' (burial service)" .)