knuckle

Any of the joints between the phalanges of the fingers.

(by extension) A mechanical joint.

A cut of meat.

(sports, billiards, snooker, pool) The curved part of the cushion at the entrance to the pockets on a cue sports table.

The kneejoint of a quadruped, especially of a calf; formerly used of the kneejoint of a human being.

(obsolete) The joint of a plant.

(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.

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; a knuckle duster.

(skiing, snowboarding) The rounded point where a flat changes to a slope on a piste.