Ostentatious clothes or decoration (6)
I believe the answer is:
finery
<span class="explanation-format__ClueExplanation">I believe this clue is a double definition.<br/ ><br/ >'<span class="explanation-format__original">ostentatious clothes</span>' is the first definition.<br/ ><span class="explanation-format__explanation">(I've seen this before)</span><br/ ><br/ >'<span class="explanation-format__original">decoration</span>' is the second definition.<br/ ><span class="explanation-format__explanation">(I have seen 'Ostentatious decoration ' mean 'finery' so perhaps 'decoration' could also mean 'finery')</span><br/ ><br/ ></span>
(Other definitions for finery that I've seen before include "Elaborate clothing, jewellery etc" , "Elaborate clothes and accessories" , "Regalia" , "smart clothes" , "Ostentatious clothes" .)