A novel once again (4)
I believe the answer is:
anew
'once again' is the definition.
(I've seen this before)
'a novel' is the wordplay.
'novel' becomes 'new' (novel means new or fresh).
'a'+'new'='ANEW'
(Other definitions for anew that I've seen before include "Wane in a different way, again" , "Again but differently" , "From the beginning again" , "Once more (poetic)" , "Afresh" .)