Volcano (4)
I believe the answer is:
etna
<span class="explanation-format__ClueExplanation">'<span class="explanation-format__original">volcano</span>' is the definition.<br/ ><span class="explanation-format__explanation">(Mount Etna)</span><br/ ><br/ >This is all the clue.<br/ ></span>
(Other definitions for etna that I've seen before include "Neat volcano overturned" , "it may produce steam and ash" , "Italian volcano" , "Sicilian landmark" , "Threatening mountain" .)