undersea

1 of 2

adjective

un·​der·​sea ˌən-dər-ˈsē 

1

: being or carried on under the sea or under the surface of the sea

undersea oil deposits

undersea fighting

2

: designed for use under the surface of the sea

an undersea fleet

undersea

2 of 2

adverb

variants or underseas

ˌən-dər-ˈsēz 

: under the sea : beneath the surface of the sea

photographs taken undersea

Examples of undersea in a Sentence

Adjective

They are conducting undersea research.

Recent Examples on the Web

Adjective

Dive to find undersea treasures like the Champagne Reef, which explodes with tiny bubbles from active fumaroles (where hot volcanic gas is released). —Paul Rubio, AFAR Media, 23 Dec. 2024

What's New The Yi Peng 3, the Chinese cargo ship suspected of damaging undersea telecom cables in the Baltic Sea last month, may have attempted to sabotage them 10 days before, reports suggest. —John Feng, Newsweek, 18 Dec. 2024

The Matsu incident was a wake-up call for the main island of Taiwan, which relies on 14 undersea cables for the bulk of its internet service. —Joshua Keating, Vox, 16 Dec. 2024

Put simply, this is a giant eddy caused by a rotating column of water that forms above undersea mountains. —David Szondy, New Atlas, 16 Dec. 2024

Word History

First Known Use

Adjective

1613, in the meaning defined at sense 1

Adverb

1645, in the meaning defined above

Kids Definition

undersea

adjective

un·​der·​sea

ˈən-dər-ˈsē

1

: being or carried on under the sea or under the surface of the sea

undersea oil deposits

undersea warfare

2

: designed for use under the surface of the sea

undersea fleet