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

The helmets survived in exceptional condition thanks to a combination of sediment and mineral deposits that formed around them underwater.

From Science Daily • Jun. 8, 2026

Antelope Reef is a small, teardrop-shaped island in the north-western corner of the South China Sea and, until recently, almost entirely underwater.

From BBC • Jun. 3, 2026

The reason we’re underwater is because most of us is hidden.

From Los Angeles Times • Jun. 1, 2026

U.S. forces used underwater robots to clear it of mines in the weeks leading up to the operation.

From The Wall Street Journal • May 30, 2026

The underwater road stretched far ahead, toward a jumble of murky shapes.

From "The Wild Robot Protects" by Peter Brown

Related Words

• submerged
• undersea