What is "knuckle"

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.

1. To submit to in a contest; to yield to. [Colloq.] See To knock under, under Knock, v. i.

2. To apply one's self vigorously or earnestly to; as, to knuckle to work. [Colloq.]

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

Knuckle \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 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.

mid-14c., knokel "finger joint; any joint of the body, especially a knobby one; morbid lump or swelling;" common Germanic (cognates: Middle Low German knökel, Middle Dutch cnockel, German knöchel), literally "little bone," a diminutive of Proto-Germanic root *knuck- "bone" (compare German Knochen "bone).\n

\nAs a verb from 1740, originally in the game of marbles. To knuckle down "apply oneself earnestly" is 1864 in American English, extended from marbles (putting a knuckle on the ground in assuming the hand position preliminary to shooting); to knuckle under "submit, give in" is first recorded 1740, supposedly from the former more general sense of "knuckle" and here meaning "knee," hence "to kneel." The face-busting knuckle-duster is from 1858 (a duster was a type of protective coat worn by workmen).

n. 1 Any of the joints between the phalanges of the fingers. 2 (context by extension English) A mechanical joint. 3 A cut of meat. 4 (context sports billiards snooker pool English) The curved part of the cushion at the entrance to the pockets on a cue sports table. 5 The kneejoint of a quadruped, especially of a calf; formerly used of the kneejoint of a human being. 6 (context obsolete English) The joint of a plant. 7 (context shipbuilding English) 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. 8 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. vb. To apply pressure, or rub or massage with one's knuckles.

n. a joint of a finger when the fist is closed [syn: knuckle joint, metacarpophalangeal joint]

1. v. press or rub with the knuckles

2. shoot a marble while keeping one's knuckles on the ground

A knuckle is a joint on the hand.

Knuckle or knuckles may also refer to:

Knuckle is a 2012 film about the secretive world of Irish Traveller bare-knuckle boxing. The film was made in stages over 12 years.

The knuckles are the joints of the fingers which are brought into prominence when the hand is clenched and a fist is made. The word is cognate to similar words in other Germanic languages, such as the Dutch "Knokkel" (knuckle) or German "Knöchel" (ankle), i.e., Knöchlein, the diminutive of the German word for bone (Knochen). Anatomically, it is said that the knuckles consist of the metacarpophalangeal (MCP) and interphalangeal (IP) joints of the finger. The knuckles at the base of the fingers may be referred to as the 1st or major knuckles while the knuckles at the midfinger are known as the 2nd and 3rd, or minor, knuckles. However, the ordinal terms are used inconsistently, and can be found referring to any of the knuckles.

The physical mechanism behind the popping or cracking sound heard when cracking joints such as knuckles is still uncertain, although it is widely believed to be caused by synovial fluid filling the vacuum left by the joint's displacement.