A spirited author? (11)
I believe the answer is:
ghostwriter
'a spirited author?' is the definition.
'ghostwriter' can be an answer for 'author?' (ghostwriter is a kind of author). I am not sure about the 'a spirited' bit.
'spirited author?' is the wordplay.
'spirited' becomes 'ghost' (I am not sure about this - if you are sure you should believe this answer much more).
'author?' becomes 'writer' ('writer' can be a synonym of 'author').
'ghost'+'writer'='GHOSTWRITER'
(Other definitions for ghostwriter that I've seen before include "Maybe Sheridan Le Fanu" , "second involved in an autobiography?" , "scibe for the incapable" , "Author denied credit" .)