literally a bend or turn, is used in mechanics particularly to denote a contrivance for converting a rotary into a reciprocating motion, and vice versa, either by means of a simple rectangular bend at the extremity of an axis, or by a double bend in any other part of its rectilinear length, thus . As the axis revolves, the crank describes the circumference of a circle, and gives the rod attached to it a reciprocating motion. There are various modifications of this useful contrivance. See Mechanics, and Steam-Engine.

in sea language, is applied to a vessel when, from too much top weight, or the want of sufficient ballast or cargo, or from any other cause, she cannot bear much sail without danger of oversetting. It also denotes an iron brace for supporting the lanterns on the poop-quarters of a ship.