Sumatra

American  

[soo-mah-truh] / sʊˈmɑ trə /

noun

1. a large island in the W part of Indonesia. 164,147 sq. mi. (425,141 sq. km).

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Sumatra British  

/ sʊˈmɑːtrə /

noun

1. Indonesian spellling: Sumatera.  a mountainous island in W Indonesia, in the Greater Sunda Islands, separated from the Malay Peninsula by the Strait of Malacca: Dutch control began in the 16th century; joined Indonesia in 1945. Northern coastal areas, esp Aceh province, suffered devastation as a result of the Indian Ocean tsunami of December 2004. Pop: 42 409 510 (2000). Area: 473 606 sq km (182 821 sq miles)

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Sumatra Cultural  

1. Island in Indonesia in the Indian Ocean northwest of Java and west of Malaysia.

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Discover More

Though much of the island is covered by swampland and impenetrable rain forest, Sumatra's industries — including oil, coal, gold, silver, rubber, timber, and tobacco — produce over half of Indonesia's income.

Other Word Forms

• Sumatran adjective

Example Sentences

They are among 26,000 flood survivors still displaced after a monsoon deluge struck their villages on Sumatra island last year.

From Barron's • Feb. 25, 2026

Pictures showing the carcass of a Sumatran elephant, another critically endangered species, being swept away by floods in Aceh in northern Sumatra went viral on social media last week.

From BBC • Dec. 11, 2025

An unusual silence in the forests of north Sumatra in Indonesia is worrying wildlife experts and conservationists.

From BBC • Dec. 11, 2025

Torrential monsoon season deluges paired with two separate tropical cyclones last week dumped heavy rain across all of Sri Lanka and parts of Indonesia's Sumatra, southern Thailand and northern Malaysia.

From Barron's • Dec. 2, 2025

As a result, what are now the shallow seas between Asia and the Indonesian islands of Sumatra, Borneo, Java, and Bali became dry land.

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