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

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

The recent floods have also damaged a number of orangutan research centres in Sumatra - including at Ketambe, the world's first orangutan research centre, in Aceh.

From BBC • Dec. 11, 2025

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

Monsoon rains paired with two rare tropical storm systems, sometimes known in the region as cyclones, dumped record deluges across Sri Lanka, and parts of Indonesia's Sumatra, southern Thailand and northern Malaysia last week.

From Barron's • Dec. 3, 2025

It was two days later before the skies cleared and Nat could check their position and set his course once more for Sumatra.

From "Carry On, Mr. Bowditch" by Jean Lee Latham