Theory; dissertation (6)
I believe the answer is:
thesis
<span class="explanation-format__ClueExplanation">I believe this is a double definition.<br/ ><br/ >'<span class="explanation-format__original">theory</span>' is the first definition.<br/ ><span class="explanation-format__explanation">(I've seen this before)</span><br/ ><br/ >'<span class="explanation-format__original">dissertation</span>' is the second definition.<br/ ><span class="explanation-format__explanation">(I know that dissertation can be written as thesis)</span><br/ ><br/ ></span>
(Other definitions for thesis that I've seen before include "Theme for an essay" , "Scholarly dissertation" , "writing following research" , "Analytical essay written for university degree" , "Learned dissertation" .)