1. A copyright-protection method of embedding a code into a digital audio or video file to attempt to thwart piracy or unlicenced use. 2. In desktop publishing, an inserted (and usually faint) overlay of an image or text onto pages of a document. Note: The watermark is usually visible on the computer screen in WYSIWIG fashion and on the printed pages of the final document. The watermark often verifies authenticity of authorship or release authority.