deface

verb3

1. •
   To damage or vandalize something, especially a surface, in a visible or conspicuous manner.

   • After the painting was defaced a decade ago, it went viral and has been a tourist attraction ever since.
2. •
   To alter a coat of arms or a flag by adding an element to it.

   • You get the Finnish state flag by defacing the national flag with the state coat of arms placed in the middle of the cross.
3. •
   To void or devalue; to nullify or degrade the face value of.

   • He defaced the I.O.U. notes by scrawling "void" over them.