An active volcano in Sicily (4)
I believe the answer is:
etna
<span class="explanation-format__ClueExplanation">'<span class="explanation-format__original">an active volcano in sicily</span>' is the definition.<br/ ><span class="explanation-format__explanation">(I've seen this in another clue)</span><br/ ><br/ >This is all the clue.<br/ ></span>
(Other definitions for etna that I've seen before include "hole in the crust" , "Natural hazard" , "burning mountain" , "Neat class of volcano in Sicily" , "Volcano in Sicily, quite neat" .)