invidens
From LSJ
ἰχθύς ἐκ τῆς κεφαλῆς ὄζειν ἄρχεται → the fish stinks from the head, a fish rots from the head down, the fish rots from the head down, fish begin to stink at the head, the fish stinks first at the head, corruption starts at the top, the rot starts at the top
