knucklebone

noun

1. (in humans) any of the bones forming a knuckle of a finger.
2. (in quadrupeds) a bone homologous with a wrist, ankle, or finger bone of humans, or its knobbed end.

noun

1. any bone forming part of a knuckle or knuckle joint

n.

1. A knobbed bone, as of a knuckle or joint.