Make fresh conclusions from Oscar Wilde novel (5)
I believe the answer is:
renew
'make fresh' is the definition.
(I've seen this in another clue)
'conclusions from oscar wilde novel' is the wordplay.
'conclusions from' suggests the final letters (the letters which conclude the words).
'novel' becomes 'new' (novel means new or fresh).
The last letters of 'oscar wilde' are 're'.
're'+'new'='RENEW'
(Other definitions for renew that I've seen before include "Transform born-again" , "Start afresh" , "Restore (worn out item)" , "Begin again" , "Reform" .)