Research dissertation (6)
I believe the answer is:
thesis
<span class="explanation-format__ClueExplanation">'<span class="explanation-format__original">research dissertation</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 thesis that I've seen before include "Subject" , "Long dissertation written to obtain university degree" , "Treatise advancing a new point of view resulting from research" , "writing following research" , "Dissertation presented for a doctorate" .)