[uhn-der-waw-ter, -wot-er]


existing or occurring under water.
designed to be used under water.
located below a ship's waterline.


beneath the water: to travel underwater.


the water beneath the surface: cold currents in the underwater.
underwaters, the depths, as of a sea, lake, etc.

Origin of underwater

First recorded in 1620–30; under- + water
Dictionary.com Unabridged Based on the Random House Unabridged Dictionary, © Random House, Inc. 2019

Related Words for underwater

submerged, undersea, immersed, sunken, submarine, subaquatic, subaqueous

Examples from the Web for underwater

Contemporary Examples of underwater

Historical Examples of underwater

  • The mud sucked at it and underwater roots caught on the vanes.


    Harry Harrison

  • When they start shelling from underwater, the Soviets are sure going to be surprised.

    The Defenders

    Philip K. Dick

  • "Then we won't be able to see what goes on underwater," he told her.

    Creatures of the Abyss

    Murray Leinster

  • Underwater it was much louder than when it had been received by the Esperance's microphone.

    Creatures of the Abyss

    Murray Leinster

  • After a long time the normal course of underwater life resumed.

    The Forgotten Planet

    Murray Leinster

British Dictionary definitions for underwater



being, occurring, or going under the surface of the water, esp the seaunderwater exploration
nautical below the water line of a vessel
(of a stock option or other asset) having a market value below its purchase value


beneath the surface of the water
Collins English Dictionary - Complete & Unabridged 2012 Digital Edition © William Collins Sons & Co. Ltd. 1979, 1986 © HarperCollins Publishers 1998, 2000, 2003, 2005, 2006, 2007, 2009, 2012

Word Origin and History for underwater

1620s, from under + water (n.). Of mortgages from 2008.

Online Etymology Dictionary, © 2010 Douglas Harper