Your knuckles are the joints in your fingers that are farthest from your fingernails. When you clench your hand into a fist, your knuckles are especially prominent.

A knuckle is the part of your hand that makes it possible to move a finger freely, and if someone offers you a "knuckle sandwich," you should politely decline, since they're actually planning to make a fist and punch you in the mouth. To knuckle is to rub with the knuckles, like when you knuckle a bit of sand out of your eye. The root of knuckle is the Proto-Germanic knuk-, "bone."

Definitions of knuckle
  1. noun
    a joint of a finger when the fist is closed
    synonyms: knuckle joint, metacarpophalangeal joint
    see moresee less
    type of:
    articulatio synovialis, diarthrosis, synovial joint
    a joint so articulated as to move freely
  2. verb
    press or rub with the knuckles
    see moresee less
    type of:
    exert pressure or force to or upon
  3. verb
    shoot a marble while keeping one's knuckles on the ground
    see moresee less
    type of:
    throw or propel in a specific direction or towards a specific objective
Word Family
F1 image

Express yourself in 25 languages

  • Learn immersively - no memorization required
  • Build skills for real-world conversations
  • Get immediate feedback on your pronunciation
Get started for $7.99/month