flōd-ȳþ, f.n: a flood-wave.
From The Medieval Bestiary website: ‘The illustration of the sawfish usually shows a large, winged dragon-like monster, racing with a ship or catch fish or sometimes both. Kongelige Bibliotek, Gl. kgl. S. 3466 8º (f. 43v) shows two sawfish, one diving into the sea to catch fish, the other rising from the sea to block the wind from a ship full of alarmed sailors.’