Source : Webster's Revised Unabridged Dictionary (1913)

Chin \Chin\, n. [AS. cin, akin to OS. kin, G kinn, Icel. kinn,
   cheek, Dan. & Sw. kind, L. {gena}, Gr. ?; cf. Skr. hanu.
   [root]232.]
   1. The lower extremity of the face below the mouth; the point
      of the under jaw.

   2. (Zo["o]l.) The exterior or under surface embraced between
      the branches of the lower jaw bone, in birds.

Source : WordNet®

chin
     n 1: the protruding part of the lower jaw [syn: {mentum}]
     2: Kamarupan languages spoken in western Burma and Bangladesh
        and easternmost India [syn: {Kuki}, {Kuki-Chin}]
     [also: {chinning}, {chinned}]

chin
     v : in gymnastics: raise oneself while hanging from one's hands
         until one's chin is level with the support bar [syn: {chin
         up}]
     [also: {chinning}, {chinned}]