Dash! There's coal in it! (7)
I believe the answer is:
scuttle
'dash' is the definition.
(thesaurus)
I cannot understand how the rest of the clue works.
Can you help me to learn more?
(Other definitions for scuttle that I've seen before include "fuel container" , "container for nuts" , "Rush" , "Ruin" , "Sink one's ship deliberately" .)