Gathering in university entertained by comical aunt dancing (12)
I believe the answer is:
accumulation
'gathering' is the definition.
(thesaurus)
'university entertained by comical aunt dancing' is the wordplay.
'university' becomes 'u' (abbreviation for university).
'entertained by' indicates putting letters inside (I've seen this in other clues).
'dancing' indicates an anagram.
'comical'+'aunt'='comicalaunt'
'comicalaunt' anagrammed gives 'accumlation'.
'u' going within 'accumlation' is 'ACCUMULATION'.
'in' acts as a link.
(Other definitions for accumulation that I've seen before include "Build-up" , "Process of gathering" , "Growth of capital" .)