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

Flanked by four wall-size photographs of vast, overhead perspectives of the deep blue Indian Ocean, it’s easy to feel small among the giant panels.

From Los Angeles Times • Jun. 17, 2026

A new, though extinct, species of whale was also identified among the nearly 500 skeletons found up to 7,000 metres deep along a 1,200 kilometre corridor of bones in the Indian Ocean west of Australia.

From Barron's • Jun. 10, 2026

The waters off the Indian Ocean coast where throngs of swimmers will soon congregate are home to the world’s three most-dangerous shark species.

From The Wall Street Journal • May 31, 2026

Before the Seychelles population was wiped out, the species occupied an even larger range that stretched more than 12,000 kilometers from Vanuatu in the Pacific Ocean to the Seychelles in the Indian Ocean.

From Science Daily • May 28, 2026

After the ceremony, I walked back to the river and watched it meander on its way to where, many miles distant, it emptied into the Indian Ocean.

From "Long Walk to Freedom" by Nelson Mandela