Total fool (3)
'total fool' is the definition.
(I've seen this in another clue)
This is the entire clue.
(Other definitions for idiot that I've seen before include "Unwise person" , "'The -----'. novel by Dostoyevsky (1868)" , "Fool, silly person" , "Clot" , "The - (Dostoievsky)" .)
(Other definitions for ass that I've seen before include "Silly fool or beast of burden" , "Silly fellow in passionate state" , "Animal related to horses" , "Idiotic animal" , "Braying animal" .)