Strobe light gas
I believe the answer is:
xenon
<span class="explanation-format__ClueExplanation">'<span class="explanation-format__original">strobe light gas</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 xenon that I've seen before include "Noble element" , "One of the noble set" , "Noble gas used in lamps" , "Gas used in bright lamps" , "Rare gas" .)