Explosive, for short (5)
I believe the answer is:
nitro
<span class="explanation-format__ClueExplanation">'<span class="explanation-format__original">explosive for short</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 nitro that I've seen before include "The whole universe" , "Explosive liquid" , "explosive material" .)