l]
noun, verb, -led, -ling.| 1. | a joint of a finger, esp. one of the articulations of a metacarpal with a phalanx. |
| 2. | the rounded prominence of such a joint when the finger is bent. |
| 3. | a joint of meat, consisting of the parts about the carpal or tarsal joint of a quadruped. |
| 4. | an angle or protrusion at the intersection of two members or surfaces, as in the timbers of a ship or in a roof. |
| 5. | brass knuckles. |
| 6. | a cylindrical projecting part on a hinge, through which an axis or pin passes; the joint of a hinge. |
| 7. | (in a wire mesh) a bend in a wire crossing another wire. |
| 8. | (on a chair arm) one of the ridges left at the front end by longitudinal flutes carved to accommodate the fingers. |
| 9. | Nautical. a pronounced edge formed by a change in the form of the shell of a hull. |
| 10. | to rub or press with the knuckles. |
| 11. | Marbles. to shoot (a marble) from the thumb and forefinger. |
| 12. | knuckle down,
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knuckle under (to (so/sth))
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knuckle knuck·le (nŭk'əl)
n.
The prominence of the dorsal aspect of a joint of a finger, especially of one of the joints that connect the fingers to the hand.
A rounded protuberance formed by the bones in a joint.
A kink or loop of intestine, as in a hernia.
knuckle under
Also, knuckle down. Give in, acknowledge defeat, as in The dean refused to knuckle under to the graduate students' demands, or He was forced to knuckle down before their threats of violence. Presumably this idiom alludes to a kneeling position with hands on the ground, knuckles down. [Mid-1700s]