Ostentatiously rich (7)
I believe the answer is:
opulent
<span class="explanation-format__ClueExplanation">'<span class="explanation-format__original">ostentatiously rich</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 opulent that I've seen before include "extremely elegant" , "'Rich, sumptuous (7)'" , "Ostentatiously costly and luxurious" , "Moneyed" , "Wealthy, got lots of money" .)