Author Edith briefly backed Norwegian one (5)
I believe the answer is:
ibsen
'norwegian one' is the definition.
Although both the answer and definition are singular nouns, I don't see how one could define the other.
'author edith briefly backed' is the wordplay.
'author edith' becomes 'Nesbit' (Edith Nesbit aka E Nesbit).
'briefly' means to remove the last letter.
'backed' shows that the letters should be reversed in order.
'nesbit' with its last letter removed is 'nesbi'.
'nesbi' written backwards gives 'IBSEN'.
(Other definitions for ibsen that I've seen before include "Scandinavian playwright" , "Linesman" , "Norwegian dramatist, Henrik (1828-1906)" , ""Doll's House" dramatist" , "foreign author" .)