Barbecue leftover? (3)
I believe the answer is:
ash
'barbecue leftover?' is the definition.
(I've seen this in another clue)
This is all the clue.
(Other definitions for ash that I've seen before include "Rowan tree is also called the mountain . . ." , "Knotty - - (Ken Dodd)" , "Tree; fire residue" , "What's left of the fire" , "sort of tree?" .)