Dark wood (5)
I believe the answer is:
ebony
<span class="explanation-format__ClueExplanation">'<span class="explanation-format__original">dark wood</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>
(Other definitions for ebony that I've seen before include "Heavy hard wood, usually black" , "'Hard, dark wood (5)'" , "Dark hardwood" , "Tree having black wood" , "hard stuff" .)