Defraud a character shipwrecked in novel for seafood (6)
I believe the answer is:
scampi
'seafood' is the definition.
(type of seafood)
'defraud a character shipwrecked in novel' is the wordplay.
'defraud' becomes 'scam' (to scam someone is to defraud them).
'a character shipwrecked in novel' becomes 'Pi' (in the novel Life of Pi).
'scam'+'pi'='SCAMPI'
'for' is the link.
(Other definitions for scampi that I've seen before include "Dish of crustaceans" , "Breaded prawns" , "Large prawns as food" , "Fried seafood" , "Fish dish, often in rings" .)