He sits awkwardly producing dissertation (6)
I believe the answer is:
thesis
'dissertation' is the definition.
(I know that dissertation can be written as thesis)
'he sits awkwardly' is the wordplay.
'awkwardly' indicates anagramming the letters.
'he'+'sits'='hesits'
'hesits' is an anagram of 'THESIS'.
'producing' acts as a link.
(Other definitions for thesis that I've seen before include "Long dissertation written to obtain university degree" , "Essay putting forward a particular view" , "Lengthy written essay for university degree" , "Long research essay or treatise written for university degree" , "Academic dissertation" .)