To deface means to deliberately damage or spoil the appearance of something, especially by drawing, writing, or scratching on it. When someone defaces a desk by carving their initials into it, they're ruining its surface. When vandals deface a statue with spray paint, they're damaging something that was meant to be beautiful or meaningful.

The word emphasizes visible damage that mars how something looks. You might accidentally scratch a book, but defacing it means deliberately drawing on the pages or tearing them up. Someone who defaces a library book by scribbling in the margins makes it harder for the next person to read and enjoy.

Defacement can be small, like crossing out words on a poster, or large, like covering a building with graffiti. Ancient Romans who didn't like an emperor would sometimes deface his coins by scratching out his portrait.

People get upset about defacement because it shows disrespect. Whether it's a park bench, a painting, or a monument, defacing something means treating it carelessly or even contemptuously, ignoring that others might value it.