Phrase (5)
I believe the answer is:
idiom
<span class="explanation-format__ClueExplanation">'<span class="explanation-format__original">phrase</span>' is the definition.<br/ ><span class="explanation-format__explanation">(an idiom is a phrase or saying)</span><br/ ><br/ >This is the entire clue.<br/ ></span>
(Other definitions for idiom that I've seen before include "Eg, over the moon" , "Phrase such as over the moon" , "Linguistic peculiarity" , "'Break a leg' or 'miss the boat'" , "Expression that does not make literal sense" .)