Penitential attire (9)
I believe the answer is:
sackcloth
<span class="explanation-format__ClueExplanation">'<span class="explanation-format__original">penitential attire</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 sackcloth that I've seen before include "With ashes, it's a sign of repentance" , "part of repentance" , "In which penitent is" , "Penitent's attire" , "rough stuff" .)