Non-literal expression (5)
I believe the answer is:
<span class="explanation-format__ClueExplanation">'<span class="explanation-format__original">non-literal expression</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 idiom that I've seen before include "Form or variety of language" , "Language used by people or group, vernacular" , "Artistic style" , "Word usage peculiar to a specific group" , "Figure of speech" .)