Knuckle Joint
a joint in which a projection on each leg or leaf of a machine or implement is inserted in corresponding recesses in the other, the two being connected by a pin or a pivot on which they mutually turn. The legs of dividers and the leaves of butt-hinges are examples of the true knuckle joint.
The term, however, is somewhat commonly applied to joints in which the motion is not confined to one place. KNUR AND SPELL (called by Strutt "Northern Spell"), an old English game played with a ball, which is "risen" from a trap and hit with a bat made for the purpose. The ball, called the "knur," is made of wood, a little bigger than a walnut. The bat, called a "tripstick," as it is also used to s spring the the trap or "spell," consists of a piece of hard wood, 6 by 4 inches, and 1 inch thick (the pommel), attached to a supple handle from 3 to 4 feet long, which the player grasps with both hands, giving the full swing of his body with the stroke. The game consists of the cumulative distance of a given number of strokes, the player who has the greatest number of yards being the winner.