Physical matter (9)
I believe the answer is:
substance
<span class="explanation-format__ClueExplanation">'<span class="explanation-format__original">physical matter</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 substance that I've seen before include "power" , "Subject matter" , "wealth" , "Physical matter" , "Matter or material that a thing is made of" .)