Brain membrane
(Another definition for dura mater that I've seen is " membrane".)
(Another definition for duramater that I've seen is " Membrane".)
<span class="explanation-format__ClueExplanation">'<span class="explanation-format__original">brain membrane</span>' is the definition.<br/ ><span class="explanation-format__explanation">(I've seen this in another clue)</span><br/ ><br/ >This is the entire clue.<br/ ></span>
(Another definition for dura that I've seen is " Indian grass".)