Impossible to read (9)
I believe the answer is:
illegible
<span class="explanation-format__ClueExplanation">'<span class="explanation-format__original">impossible to read</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 illegible that I've seen before include "Hard to read" , "Too messy to read" , "Not capable of being read" , "Unreadable" , "Impossible to read" .)