Blackish wood (5)
I believe the answer is:
ebony
<span class="explanation-format__ClueExplanation">'<span class="explanation-format__original">blackish wood</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 ebony that I've seen before include "hard stuff" , "Hard wood used for black piano keys and in cabinetwork" , "Heavy hard wood, usually black" , "Hard dark-coloured wood" , "Tree with blackish wood" .)