\Coun"ter*mark`\ (-m?rk`), n.
1. A mark or token added to those already existing, in order
   to afford security or proof; as, an additional or special
   mark put upon a package of goods belonging to several
   persons, that it may not be opened except in the presence
   of all; a mark added to that of an artificer of gold or
   silver work by the Goldsmiths' Company of London, to
   attest the standard quality of the gold or silver; a mark
   added to an ancient coin or medal, to show either its
   change of value or that it was taken from an enemy.
2. (Far.) An artificial cavity made in the teeth of horses
   that have outgrown their natural mark, to disguise their
   age.

\Coun`ter*mark"\ (koun`t[~e]r*m[aum]rk"), v. t.
To apply a countermark to; as, to countermark silverware; to
countermark a horse's teeth.