1. 1. A mark showing the greatest height to which water has risen.
   2. A line indicating the heights of high and low tide.
2. 1. A translucent design impressed on paper during manufacture and visible when the paper is held to the light.
   2. The metal pattern that produces this design.

1. To mark (paper) with a watermark.
2. To impress (a pattern or design) as a watermark.

The American Heritage® Dictionary of the English Language, Fourth Edition Copyright © 2007, 2000 by Houghton Mifflin Company. Updated in 2009. Published by Houghton Mifflin Company. All rights reserved.