FUTTOCKS, the middle division of a ship’s timbers; or those parts which are situated between the floor and the top-timbers …

As the epithet hooked is frequently applied in common language to any thing bent or incurvated, and particularly to several crooked timbers in a ship, as the breast-hooks, fore-hooks, after-hooks, &c. this term is evidently derived from the lowest part or foot of the timber, and from the shape of the piece. Hence.

– Wm. Falconer’s Dictionary of the Marine (1780).