A god transfixed by university writer (6)
I believe the answer is:
author
'writer' is the definition.
(synonyms)
'a god transfixed by university' is the wordplay.
'god' becomes 'Thor' (Norse god of thunder).
'transfixed by' indicates putting letters inside.
'university' becomes 'U' (abbreviation for university).
'a'+'thor'='athor'
'athor' enclosing 'u' is 'AUTHOR'.
(Other definitions for author that I've seen before include "Ford, for example" , "Generator of written work" , "Writer of a book, say" , "Producer of written work" , "Generator, source" .)