Meaning of countermark

coun•ter•mark

Pronunciation: (n.koun'tur-märk"v.koun"tur-märk'), [key]
— Numis. Numis.
—n.
  1. Also calleda sign or device stamped on a coin after its minting.
—v.t.
  1. to stamp (a coin) with a countermark; counterstamp.
Random House Unabridged Dictionary, Copyright © 1997, by Random House, Inc., on Infoplease.