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

Officials from President Prabowo Subianto down have acknowledged the role of deforestation and overdevelopment in last year's flooding and landslides, which killed over 1,000 people in Sumatra.

From Barron's • Feb. 19, 2026

Triggered by a rare cyclone in November, the deluge killed more than 1,000 people and displaced hundreds of thousands across the island of Sumatra.

From BBC • Dec. 25, 2025

And in 2019, at least 35 people were killed when a bus plunged into a ravine on the western island of Sumatra.

From Barron's • Dec. 22, 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