Second course at meal starts with very good seafood (6)
I believe the answer is:
scampi
'seafood' is the definition.
(I've seen this before)
'second course at meal starts with very good' is the wordplay.
'starts with' indicates taking the first letters (I've seen 'start with' mean this).
'very good' becomes 'pi' (I've seen this in other clues**).
The initial letters of 'second course at meal' is 'scam'.
'scam'+'pi'='SCAMPI'
(Other definitions for scampi that I've seen before include "Type of seafood" , "Dish of crustaceans" , "Norway lobsters -- Dublin Bay prawns" , "Breaded prawns" , "Cooked Norway lobster" .)