Author Buchanan (4)
I believe the answer is:
edna
'author buchanan' is the definition.
(I've seen this in another clue)
This is all the clue.
(Other definitions for edna that I've seen before include "Barry Humphries' Dame" , "Female name" , "- O'Brien, Irish writer" , "- O'Brien, Ir. novelist" , "Dame - Everage, housewife-superstar" .)