1. A joint allowing movement in one plane only
   "The elbow is an example of a knuckle joint";
   - hinge joint
    
2. A joint of a finger; any of the joints connecting the metacarpal bones to the proximal phalanges of the fingers
   "Cracking your knuckle joints is a common habit for some people";
   - knuckle, metacarpophalangeal joint

Derived forms: knuckle joints

Type of: articulatio synovialis, diarthrosis, joint, synovial joint

Part of: finger

Encyclopedia: Knuckle joint