watermark

American  

[waw-ter-mahrk, wot-er-] / ˈwɔ tərˌmɑrk, ˈwɒt ər- /

noun

1. a mark indicating the height to which water rises or has risen, as in a river or inlet.

2. water line.

3. a figure or design impressed in some paper during manufacture, visible when the paper is held to the light.

4. Computers. Also digital watermark a small piece of code or identifiable data sequence embedded into a digital file, usually an image or an audio or video file, as a traceable marker of origin or ownership.

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verb (used with object)

1. to mark (paper or a digital file) with a watermark.

2. to impress (a design, pattern, etc.), as a watermark.

3. Computers. to place (a digital identifier) into a file.

watermark British  

/ ˈwɔːtəˌmɑːk /

noun

1. a distinguishing mark impressed on paper during manufacture, visible when the paper is held up to the light

2. another word for water line water line

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verb

1. to mark (paper) with a watermark

Other Word Forms

• unwatermarked
  adjective

Etymology

Origin of watermark

First recorded in 1625–35; water + mark ¹

Explanation

A subtle design in paper that identifies it as authentic is called a watermark. When you hold a hundred dollar bill up to the light, you can see its watermark. The term watermark comes from the way these designs are created, during the "wet paper" stage of making paper, and also from the fact that a watermark resembles a damp spot. Documents, stamps, and paper money all have watermarks that label them as genuine. Fancy writing paper often includes watermarks noting the brand. And you can also use the word for a digital marker, a signal that identifies the owner of a photo, video, or audio file. In its most literal sense, watermark means a mark showing the level of a body of water.

Example Sentences

Mazzara’s comment in the email thread with other Homeland Security attorneys was given to American Oversight with a watermark showing the agency had intended to withhold it.

From Los Angeles Times • Mar. 27, 2026

AFP fact-checkers ran the photo through AI detection tools and found it contained a SynthID, an invisible watermark meant to identify images made with Google AI.

From Barron's • Mar. 10, 2026

As Simon observed years later, the V-Discs “mark the high watermark of the big band years.”

From The Wall Street Journal • Jan. 26, 2026

When an image is accessed by a viewer, it is automatically embedded with an invisible forensic watermark which is unique to them.

From BBC • Dec. 14, 2025

Then she looked up at the old watermark left from a long-ago leak above my bed.

From "Hope Springs" by Jaime Berry

Related Words

• apex
• apogee
• upper limit