Indescribable (6)
I believe the answer is:
untold
<span class="explanation-format__ClueExplanation">'<span class="explanation-format__original">indescribable</span>' is the definition.<br/ ><span class="explanation-format__explanation">(I've seen this before)</span><br/ ><br/ >This is the entire clue.<br/ ></span>
(Other definitions for untold that I've seen before include "beyond description?" , "Unspoken - inexpressible - uncounted" , "Countless" , "Innumerable - secret" , "Too many to be counted; not narrated" .)