knuckle

Etymology

From Middle English knokel (“finger joint”), from Old English cnucel (“the juncture of two bones; knuckle; joint”), from Proto-West Germanic *knukil, from Proto-Germanic *knukilaz (“knuckle, knot, bump”), as *knukô (“bone, joint”) + *-ilaz (diminutive suffix). Cognate with Dutch knokkel (“knuckle”), Low German Knökel (“knuckle”), German Knöchel (“ankle, knuckle”), Old Norse knykill. ) of a human hand, circled in red]] ) from Schweizerhaus, Vienna]]

noun

1. Any of the joints between the bones of the fingers.
2. (by extension) A mechanical joint.
3. A cut of meat.
4. (sports, billiards, snooker, pool) 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. (obsolete) The joint of a plant.
   In the West Indies there are found, even in sandy deserts and very dry places, large canes, which at every joint or knuckle yield a good supply of fresh water 1623, Francis Bacon, The History of Dense and Rare
7. (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.
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.
   brass knuckles
9. (skiing, snowboarding) The rounded point where a flat changes to a slope on a piste.

verb

1. (transitive) To apply pressure, or rub or massage with one's knuckles (sense 1).
   He knuckled the sleep from his eyes.
2. (transitive, slang) To strike or punch.
   I could feel my big toe snap, but as he's gone down on his good knee and half swung round I knuckled him in the kidney as hard as I could hit. He's gone all the way down, so I dropped my 19 stone into the middle of his back. 2013, Lenny McLean, The Guv'nor
   Only then I knuckled him. He had to be taught a hard lesson. 2014, W. Smyth, Mama OM, page 415
3. (intransitive) To bend the fingers.
4. (intransitive) To touch one's forehead as a mark of respect.
5. (intransitive, figurative) To yield.
6. (snowboarding, skiing) To land on the knuckle (sense 9) of a curve of a slope, after a jump off a ramp that precedes the slope.