Synonyms

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.

He had met Kaye online and, calling himself Rob, told her he was a deep-sea diver "looking for a wife".

From BBC • Feb. 12, 2026

Chinese projects in Balochistan include a deep-sea port and an airport.

From The Wall Street Journal • Feb. 9, 2026

As the inventory progressed, scientists noticed that deep-sea communities changed naturally over time, likely in response to shifts in how much food reached the ocean floor.

From Science Daily • Feb. 2, 2026

Environmental campaigners warn deep-sea mining threatens marine ecosystems and will disrupt the sea floor.

From Barron's • Feb. 2, 2026

“Today is truly a momentous day,” the captain tells us, “for we shall test the diving bell and see if Caden’s knowledge of deep-sea exploration rings true.”

From "Challenger Deep" by Neal Shusterman

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