Fool from Snitterton (3)
I believe the answer is:
nit
'fool' is the definition.
(both can mean a stupid person)
'from snitterton' is the wordplay.
'from' indicates a hidden word.
'NIT' is hidden within 'snitterton'.
(Other definitions for nit that I've seen before include "Parasite's egg made of tin" , "Hair louse" , "Egg of a head louse" , "Louse; fool" , "Egg of parasitic insect" .)