Crossword Genius

Appreciative, having this much coal? (8)

Ross

I believe the answer is:

grateful

'appreciative' is the definition.
('grateful' can be similar in meaning to 'appreciative')

I cannot understand how the rest of the clue works.

(Other definitions for grateful that I've seen before include "Beholden" , "Thankful, appreciative" , "Showing thankfulness" , "Showing gratitude" , "Showing appreciation for kindness" .)

I've seen this clue in The Times.
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