Selfsame (9)
I believe the answer is:
identical
<span class="explanation-format__ClueExplanation">'<span class="explanation-format__original">selfsame</span>' is the definition.<br/ ><span class="explanation-format__explanation">(I know that selfsame can be written as identical)</span><br/ ><br/ >This is all the clue.<br/ ></span>
(Other definitions for identical that I've seen before include "Similar" , "Not any different" , "Indistinguishable" , "Selfsame" , "Impossible to tell apart" .)