a mark on an object that is additional to a mark already on that object, and that serves a purpose such as enhancing security, or noting a change in the value of that object, etc
countermark in American English
((n.) ˈkauntərˌmɑːrk, (v.) ˌkauntərˈmɑːrk)
(in numismatics)
noun
1. Also called: counterstamp
a sign or device stamped on a coin after its minting
transitive verb
2.
to stamp (a coin) with a countermark; counterstamp
Word origin
[1495–1505; (n.) ‹ MF contremarque, equiv. to contrecounter- + marquemark1; (v.) ‹ MF contremarquer, deriv. of contremarque]This word is first recorded in the period 1495–1505. Other words that entered Englishat around the same time include: pillion, runt, slope, tinsel, veteran