Fag or gasper (9)
I believe the answer is:
cigarette
<span class="explanation-format__ClueExplanation">I believe this clue is a double definition.<br/ ><br/ >'<span class="explanation-format__original">fag</span>' is the first definition.<br/ ><span class="explanation-format__explanation">(synonyms)</span><br/ ><br/ >'<span class="explanation-format__original">gasper</span>' is the second definition.<br/ ><span class="explanation-format__explanation">(I've seen this before)</span><br/ ><br/ ></span>
(Other definitions for cigarette that I've seen before include "tobacco in consumable form" , "Cylinder of tobacco" , "Fag, coffin nail" , "Gasper" , "Fag, smoke" .)