Upper assembly (6)
I believe the answer is:
senate
<span class="explanation-format__ClueExplanation">'<span class="explanation-format__original">upper assembly</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 senate that I've seen before include "House where politicians" , "Governing body of ancient Rome" , "Legislative assembly" , "Upper house of the US Congress" , "Second house of the Oireachtas" .)