The Collaborative International Dictionary of English v.0.48:

Colt \Colt\ (k[=o]lt; 110), n. [OE. colt a young horse, ass, or
   camel, AS. colt; cf. dial. Sw. kullt a boy, lad.]
   1. The young of the equine genus or horse kind of animals; --
      sometimes distinctively applied to the male, filly being
      the female. Cf. Foal.
      [1913 Webster]

   Note: In sporting circles it is usual to reckon the age of
         colts from some arbitrary date, as from January 1, or
         May 1, next preceding the birth of the animal.
         [1913 Webster]

   2. A young, foolish fellow. --Shak.
      [1913 Webster]

   3. A short knotted rope formerly used as an instrument of
      punishment in the navy. --Ham. Nav. Encyc.
      [1913 Webster]

   Colt's tooth, an imperfect or superfluous tooth in young
      horses.

   To cast one's colt's tooth, to cease from youthful
      wantonness. "Your colt's tooth is not cast yet." --Shak.

   To have a colt's tooth, to be wanton. --Chaucer.
      [1913 Webster]

The Collaborative International Dictionary of English v.0.48:

Colt's tooth \Colt's" tooth`\
   See under Colt.
   [1913 Webster]