Grain for grinding (5)
I believe the answer is:
grist
<span class="explanation-format__ClueExplanation">'<span class="explanation-format__original">grain for grinding</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 grist that I've seen before include "may be put through the mill" , "Grain for the mill" , "Corn [to the mill]" , "Grain for grinding" , "Corn for processing" .)