Characteristic style of expression (5)
I believe the answer is:
idiom
<span class="explanation-format__ClueExplanation">'<span class="explanation-format__original">characteristic style of expression</span>' is the definition.<br/ ><span class="explanation-format__explanation">(I've seen this before)</span><br/ ><br/ >This is the entire clue.<br/ ></span>
(Other definitions for idiom that I've seen before include "Form or variety of language" , "Phrase with a meaning that is not literal" , "Word usage peculiar to a specific group" , "Colloquialism" , "Phrase such as over the moon" .)