Peter in France (6)
I believe the answer is:
<span class="explanation-format__ClueExplanation">'<span class="explanation-format__original">peter in france</span>' is the definition.<br/ ><span class="explanation-format__explanation">(I've seen this before)</span><br/ ><br/ >This is all the clue.<br/ ></span>
(Other definitions for pierre that I've seen before include "Peter in France" , "See 17" , "French boy's name" , "Frenchman" , "One colouring cloth" .)