deface

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.
   • After the painting was defaced a decade ago, it went viral and has been a tourist attraction ever since.

   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.
   • 1776: Adam Smith, The Wealth of Nations
     One-and-twenty worn and defaced shillings, however, were considered as equivalent to a guinea, which perhaps, indeed, was worn and defaced too, but seldom so much so.

   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.