Knuc·kle n.
 1. The joint of a finger, particularly when made prominent by the closing of the fingers.
 2. The kneejoint, or middle joint, of either leg of a quadruped, especially of a calf; -- formerly used of the kneejoint of a human being.
    With weary knuckles on thy brim she kneeled sadly down.   --Golding.
 3. The joint of a plant. [Obs.]
 4. Mech. The joining parts of a hinge through which the pin or rivet passes; a knuckle joint.
 5. Shipbuilding A convex portion of a vessel's figure where a sudden change of shape occurs, as in a canal boat, where a nearly vertical side joins a nearly flat bottom.
 6. A contrivance, usually of brass or iron, and furnished with points, worn to protect the hand, to add force to a blow, and to disfigure the person struck;  -- called also knuckle duster, knuckles or brass knuckles. [Slang.]
 Knuckle joint Mach., a hinge joint, in which a projection with an eye, on one piece, enters a jaw between two corresponding projections with eyes, on another piece, and is retained by a pin which passes through the eyes and forms the pivot.
 Knuckle of veal Cookery, the lower part of a leg of veal, from the line of the body to the knuckle.


 knuckle duster
      n : a small metal weapon; worn over the knuckles on the back of
          the hand [syn: brass knucks, knucks, brass knuckles,
           knuckles]