'To cast one's colt's tooth' definitions:

Definition of 'To cast one's colt's tooth'

From: GCIDE

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]