defaces

Verb

deface (third-person singular simple present defaces, present participle defacing, simple past and past participle defaced)

1. To damage or vandalize something, especially a surface, in a visible or conspicuous manner.
   • 1869: George Eliot, The Legend of Jubal
     That wondrous frame where melody began / Lay as a tomb defaced that no eye cared to scan.

   Synonyms:

   disfigure, mar, obliterate, scar, vandalize

2. To void or devalue; to nullify or degrade the face value of.
   • He defaced the I.O.U. notes by scrawling "void" over them.

   Synonyms:

   cancel, devalue, nullify, void

3. (flags) 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.