Renal organ (6)
I believe the answer is:
kidney
<span class="explanation-format__ClueExplanation">'<span class="explanation-format__original">renal organ</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 kidney that I've seen before include "Glandular organ that removes waste matter from blood" , "Bean-shaped organ" , "Organ; kind; bean type" , "Organ associated with steak" , "Excretory organ" .)