I. |kau̇ntə(r)+ transitive verb
Etymology: counter- + stamp (v.)
1. : to stamp or impress (something already stamped or signed) — compare countersign
2.
a. : to countermark (a coin)
b. : to stamp (a different coin design or a countermark) onto a coin
counterstamp a coin of Heraclius on a coin of Justinian
counterstamp a Texan 8-real piece on a Mexican 5-real piece
II. ˈ ̷ ̷ ̷ ̷+ˌ- noun
Etymology: counter- + stamp (n.)
1. : a stamp or impression put upon something (as a check or paper) that has already been stamped
2. : a numismatic countermark