Shad product (3)
I believe the answer is:
roe
'shad product' is the definition.
(I've seen this in another clue)
This is all the clue.
(Other definitions for roe that I've seen before include "Fish eggs; small deer" , "Lobster's ripe ovary" , "Mass of fish eggs" , "A mass of fish-eggs" , "shy animal" .)