Sicilian smoker
I believe the answer is:
<span class="explanation-format__ClueExplanation">'<span class="explanation-format__original">sicilian smoker</span>' is the definition.<br/ ><span class="explanation-format__explanation">(I've seen this in another clue)</span><br/ ><br/ >This is the entire clue.<br/ ></span>
(Other definitions for etna that I've seen before include "Threatening mountain" , "Sicily's 15" , "Highest peak in Italy south of the Alps" , "Neat class of volcano in Sicily" , "Volcanic mount in Sicily" .)