› MONEY a mark made on some types of paper, especially paper money, that is only seen if it is held against the light, and that is used to stop illegal copies being made: The books have anti-piracy watermarks on the first page.
› IT a pattern that is added to photographs, films, and sound files to show who owns the information: digital/electronic watermark The software encodes a watermark within the DVD copy that can be traced back to the owners of the software.
› IT an image behind the main text of a computer document, for example, in official company documents or in documents used when giving a talk: A watermark is more transparent than a background and is often used as a way to display company logos during a presentation.
› FINANCE a particular level or value for an investment, used to measure its performance: Fund managers need to have a watermark to reach in each analysed investment spell.
high watermark › FINANCE the highest level reached by an investment in a particular period: Venture investments in start-up companies hit an all-time high in the San Diego region last year, although it may prove to be a high watermark.