countermark

Noun

 * 1) A mark or token added to those already existing, as a security or proof.
 * 2)  An artificial cavity made in the teeth of horses that have outgrown their natural mark, to disguise their age.

Translations

 * Catalan:
 * French:
 * Polish:
 * Spanish:

Verb

 * 1)  To apply a countermark to.
 * to countermark silverware
 * to countermark a horse's teeth