Showing appreciation of a quantity of ashes? (8)
I believe the answer is:
grateful
'showing appreciation' is the definition.
(I've seen this before)
I don't understand how the rest of the clue works.
(Other definitions for grateful that I've seen before include "Thankful, appreciative" , "Felt a rug (anag)" , "quantity of coal" , "Showing appreciation for kindness" , "Showing thankfulness" .)