Indian Ocean

American  

[in-dee-uhn oh-shuhn] / ˈɪn di ən ˈoʊ ʃən /

noun

1. an ocean south of Asia, east of Africa, and west of Australia, with its deepest section in the Java Trench. 27,243,268 square miles (70,560,000 square kilometers).

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Indian Ocean British  

noun

1. an ocean bordered by Africa in the west, Asia in the north, and Australia in the east and merging with the Antarctic Ocean in the south. Average depth: 3900 m (13 000 ft). Greatest depth (off the Sunda Islands): 7450 m (24 442 ft). In December 2004 a major undersea earthquake off Sumatra triggered a tsunami which affected large areas of the ocean as far away as east Africa, and killed an estimated 226 435 people. Area: about 73 556 000 sq km (28 400 000 sq miles)

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Indian Ocean Cultural  

1. Third-largest ocean (after the Atlantic Ocean and Pacific Ocean), extending from southern Asia to Antarctica and from eastern Africa to southeastern Australia.

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Etymology

Origin of Indian Ocean

First recorded in 1580–90

Example Sentences

It is instead aiming to blockade Iran's Gulf ports by operating its navy in the Gulf of Oman and the Indian Ocean, rather than risk its vessels close to Iran's coast.

From BBC • Apr. 14, 2026

The Bab al-Mandeb strait is a narrow passage between Yemen and the Horn of Africa that connects the Red Sea with the Indian Ocean.

From The Wall Street Journal • Apr. 14, 2026

The Indian Ocean island is a net importer of fuel, most of which comes from Oman, just south of the crucial Strait of Hormuz.

From Barron's • Apr. 8, 2026

The waterway connects the Red Sea with the Gulf of Aden in the Indian Ocean.

From MarketWatch • Mar. 26, 2026

In Chapter 19 we shall trace it across the Indian Ocean to Madagascar, while in Chapter 15 we saw that ecological difficulties kept Austronesians from establishing themselves in northern and western Australia.

From "Guns, Germs, and Steel: The Fates of Human Societies" by Jared M. Diamond