Webster’s Revised Unabridged Dictionary · 1913
Knuckle
Knuc′kle (nŭk′k'l), n. [OE. knokel, knokil, AS. cuncel; akin to D. knokkel, OFries. knokele, knokle, G. knöchel, 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 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; 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.