Research dissertation (6)
![Ross](/clue/static/ross-mug.min.png)
I believe the answer is:
thesis
'research dissertation' is the definition.
(I've seen this before)
This is all the clue.
(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" .)