underwater

American  

[uhn-der-waw-ter, -wot-er] / ˈʌn dərˈwɔ tər, -ˈwɒt ər /

adjective

1. existing or occurring under water.

2. designed to be used under water.

3. located below a ship's waterline.

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adverb

1. beneath the water.

   to travel underwater.

noun

1. the water beneath the surface.

   cold currents in the underwater.

2. underwaters, the depths, as of a sea, lake, etc.

underwater British  

/ ˈʌndəˈwɔːtə /

adjective

1. being, occurring, or going under the surface of the water, esp the sea

   underwater exploration

2. nautical below the water line of a vessel

3. (of a stock option or other asset) having a market value below its purchase value

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adverb

1. beneath the surface of the water

Etymology

Origin of underwater

First recorded in 1620–30; under- + water

Example Sentences

They suggest that while an underwater landslide did occur, it did not directly create the wrinkles.

From Science Daily • Apr. 3, 2026

Firms’ margins would be pummeled and consumer wage growth dragged underwater.

From Barron's • Apr. 2, 2026

Don’t miss the Tropical Rainforest Aviary for free-flight birds or the Arctic Passage, where you can watch polar bears and seals swim underwater.

From Salon • Mar. 31, 2026

The Labs also had to figure out ways to create underwater conduits, as well as switching centers that could manage the growing number of customers and escalating amounts of data.

From The Wall Street Journal • Mar. 28, 2026

Natalie tumbled along the rough rooftop, trying to grab hold of something, anything, and then suddenly the solid ground underneath her was gone and she was underwater again.

From "Two Degrees" by Alan Gratz

Related Words

• submerged
• undersea