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).

---

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)

---

Sumatra Cultural  

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

---

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

Derived Forms

• Sumatran
  adjective

Example Sentences

The only documented example occurred in Sumatra, where two large earthquakes struck three months apart in 2004 and 2005.

From Science Daily • May 2, 2026

Home Minister Tito Karnavian, who leads a reconstruction task force in Sumatra, told lawmakers on February 18 that only 8,300 temporary structures -- roughly half of the 16,688 planned -- have been built.

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

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

The last supervolcano eruption on Earth was at Toba, in northern Sumatra, seventy-four thousand years ago.

From "A Short History of Nearly Everything" by Bill Bryson