[knuck.le] n [ME knokel; akin to MHG knochel knuckle] (14c) 1 a: the rounded prominence formed by the ends of the two adjacent bones at a joint--used esp. of those at the joints of the fingers b: the joint of a knuckle
2: a cut of meat consisting of the tarsal or carpal joint with the adjoining flesh
3: something resembling a knuckle: as a (1): one of the joining parts of a hinge through which a pin or rivet passes (2): knuckle joint b: the meeting of two surfaces at a sharp angle (as in a roof) c: a pivotal point
4. pl: a set of metal finger rings or guards attached to a transverse piece and worn over the front of the doubled fist for use as a weapon--called also brass knuckles -- knuck.led adj
[2]knuckle vb knuck.led ; knuck.ling vi (1740): to place the knuckles on the ground in shooting a marble ~ vt: to press or rub with the knuckles