Mariana Trench

American  

[mair-ee-ah-nuh trench, mar-] / ˈmɛər iˌɑ nə ˈtrɛntʃ, ˈmær- /

noun

1. the world’s deepest oceanic trench, a crescent-shaped depression located in the western Pacific Ocean, south and west of the Mariana Islands: site of the Challenger Deep.

---

Etymology

Origin of Mariana Trench

First recorded in 1930–35; named after the Mariana Islands

Example Sentences

Temperatures can reach more than 400 degrees Fahrenheit; the pressure can be as high as at the bottom of the Mariana Trench in the Pacific Ocean, the deepest point in the world’s oceans.

From The Wall Street Journal • Oct. 29, 2025

Microplastics have been found in even the most remote corners of the Earth, such as the Mariana Trench, the deepest oceanic trench on the planet.

From Slate • Apr. 27, 2024

These so-called microplastics are spread throughout the water column and have been found in every corner of the globe, from Mount Everest, the highest peak, to the Mariana Trench, the deepest trough.

From National Geographic • Feb. 21, 2024

The plan was to head to the deepest place on the planet, the very bottom of the Mariana Trench, a narrow, underwater canyon, which lies in the Pacific Ocean, off the coast of Guam.

From BBC • Nov. 18, 2023

A hug from Mom hadn’t fixed it, but it had pulled Cat’s heart from the bottom of the Mariana Trench to somewhere around sea level.

From "Caterpillar Summer" by Gillian McDunn