Fish with a bite that's shocking (9)
I believe the answer is:
whitebait
'fish' is the definition.
(I know that whitebait is a type of fish)
'with a bite that's shocking' is the wordplay.
'that's shocking' indicates anagramming the letters (letters shocked or shaken).
'with'+'a'+'bite'='withabite'
'withabite' with letters rearranged gives 'WHITEBAIT'.
(Other definitions for whitebait that I've seen before include "Fish eaten in quantity" , "Small fry as food" , "Small fried fish" , "Small edible fish" , "Young of herrings" .)