\Knuc"kle\, n. [OE. knokel, knokil, AS. cuncel; akin to
D. knokkel, OFries. knokele, knokle, G. kn["o]chel, Sw.
knoge, Dan. knokkel, G. knochen bone, and perh. to E. knock.]
1. The joint of a finger, particularly when made prominent by
   the closing of the fingers. --Davenant.
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.] --Bacon.
4. (Mech.) The joining pars 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; as, brass
   knuckles; -- called also {knuckle duster}. [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.

\Knuc"kle\, v. i. [imp. & p. p. {Knuckled};; p. pr. &
vb. n. {Knuckling}.]
To yield; to submit; -- used with down, to, or under.
{To knuckle to}.
(a) To submit to in a contest; to yield to. [Colloq.] See {To
    knock under}, under {Knock}, v. i.
(b) To apply one's self vigorously or earnestly to; as, to
    knuckle to work. [Colloq.]

\Knuc"kle\, v. t.
To beat with the knuckles; to pommel. [R.] --Horace Smith.