A mark indicating the height to which water has risen, or at which it has stood; the usual limit of high or low water.
- A mark showing the greatest height to which water has risen.
- A line indicating the heights of high and low tide.
- A translucent design impressed on paper during manufacture and visible when the paper is held to the light.
- The metal pattern that produces this design.
- To mark (paper) with a watermark.
- To impress (a pattern or design) as a watermark.