countermark

[ noun koun-ter-mahrk; verb koun-ter-mahrk ]
/ noun ˈkaʊn tərˌmɑrk; verb ˌkaʊn tərˈmɑrk /
Numismatics

noun

Also called counterstamp. a sign or device stamped on a coin after its minting.

verb (used with object)

to stamp (a coin) with a countermark; counterstamp.

Origin of countermark

1495–1505; (noun) < Middle French contremarque, equivalent to contre counter- + marque mark1; (v.) < Middle French contremarquer, derivative of contremarque
Dictionary.com Unabridged Based on the Random House Unabridged Dictionary, © Random House, Inc. 2019