: of, relating to, or being the parts of the ocean below 6000 meters (about 20,000 feet)
Examples of hadal in a Sentence
Recent Examples on the Web
The creatures live 5,800 to 9,500 meters (19,000 to 30,000 feet) below the ocean’s surface in what’s called the hadal zone.
—
Katie Hunt, CNN Money, 29 Dec. 2025
Studies suggest hadal zones can bury up to 70 times more carbon per square meter than the average seafloor.
—Ingmar Rentzhog, Forbes.com, 14 Aug. 2025
What to Know About the Project The three-year research initiative will focus on deep-sea areas in the Pacific Ocean, including parts of the hadal zone, which extends to depths of 36,000 feet and accounts for 45 percent of the ocean.
—Justin Gest, Newsweek, 20 Jan. 2025
Arwen becomes fascinated by the world beneath the ocean’s surface, where there are undersea mountain ranges that can be higher than the Rockies, and by the water’s layered zones, including the deepest, the hadal—or hadopelagic—zone, which gives the story its title.
—Cressida Leyshon, The New Yorker, 30 June 2024
Beyond a certain depth, specifically below about 200 meters (656 feet), the ocean enters the mesopelagic zone and extends into the abyssal and hadal zones, reaching depths of over 11,000 meters (36,000 feet).
—Scott Travers, Forbes, 28 Feb. 2024
Below that, only one destination more mysterious and more feared: Hades, or the hadal zone, below 20,000 feet.
—Carl Hoffman, Washington Post, 1 Aug. 2023
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Katie Hunt, CNN Money, 29 Dec. 2025
Studies suggest hadal zones can bury up to 70 times more carbon per square meter than the average seafloor.
—Ingmar Rentzhog, Forbes.com, 14 Aug. 2025
What to Know About the Project The three-year research initiative will focus on deep-sea areas in the Pacific Ocean, including parts of the hadal zone, which extends to depths of 36,000 feet and accounts for 45 percent of the ocean.
—Justin Gest, Newsweek, 20 Jan. 2025
Arwen becomes fascinated by the world beneath the ocean’s surface, where there are undersea mountain ranges that can be higher than the Rockies, and by the water’s layered zones, including the deepest, the hadal—or hadopelagic—zone, which gives the story its title.
—Cressida Leyshon, The New Yorker, 30 June 2024
Beyond a certain depth, specifically below about 200 meters (656 feet), the ocean enters the mesopelagic zone and extends into the abyssal and hadal zones, reaching depths of over 11,000 meters (36,000 feet).
—Scott Travers, Forbes, 28 Feb. 2024
Below that, only one destination more mysterious and more feared: Hades, or the hadal zone, below 20,000 feet.
—Carl Hoffman, Washington Post, 1 Aug. 2023
Cite this Entry
“Hadal.” Merriam-Webster.com Dictionary, Merriam-Webster, https://www.merriam-webster.com/dictionary/hadal. Accessed 13 Jan. 2026.
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