deep-sea

American

[deep-see] / ˈdipˈsi /

adjective

of, pertaining to, in, or associated with the deeper parts of the sea.

deep-sea fishing; deep-sea diver.

deep-sea British

noun

(modifier) of, found in, or characteristic of the deep parts of the sea

deep-sea fishing

"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

Etymology

Origin of deep-sea

First recorded in 1620–30

Example Sentences

Examples are provided to illustrate real-world usage of words in context. Any opinions expressed do not reflect the views of Dictionary.com.

Scientists have long considered deep-sea hydrothermal vents as possible sites where life began.

From Science Daily • Apr. 3, 2026

"The affected area is of exceptional ecological value, with fragile deep-sea ecosystems and some of the highest biodiversity in the Mediterranean basin."

From Barron's • Mar. 15, 2026

The scientists examined genetic material collected from volcanic lakes in Iceland and from deep-sea hydrothermal vents located more than two kilometers beneath the North Atlantic Ocean.

From Science Daily • Mar. 14, 2026

A US deep-sea treasure hunter who refused to disclose the location of a famed shipwreck's gold coins has been released from prison after a decade, with 500 coins still unaccounted for.

From BBC • Mar. 14, 2026

A tuna tower is the tall aluminum platform that sits above the cockpit on a deep-sea charter boat.

From "Flush" by Carl Hiaasen

Definitions and idiom definitions from Dictionary.com Unabridged, based on the Random House Unabridged Dictionary, © Random House, Inc. 2023