📖 WordNook

knuckle

noun
  1. a joint of a finger when the fist is closed
    “The fighter's knuckles hurt after the cage match.”
    knuckle joint
verb
  1. to shoot a marble while keeping one's knuckles on the ground
    “I knuckle marbles.”
  2. to press or rub with the knuckles
    “Can you knuckle my shoulders?”