territorial waters

American  

[ter-i-tawr-ee-uhl waw-terz, wot-erz] / ˈtɛr ɪˌtɔr i əl ˈwɔ tərz, ˈwɒt ərz /

plural noun

International Law.

1. the waters of a coastal state or nation that are regarded as under the jurisdiction of the state or nation, traditionally within 3 miles (4.8 km) of the shore, but with claims by certain coastal nations that have extended to 12 or even 200 miles (20 or 322 km).

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territorial waters British  

plural noun

1. the waters over which a nation exercises jurisdiction and control

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Etymology

Origin of territorial waters

First recorded in 1870–75

Example Sentences

China says it is acting inside its territorial waters.

From The Wall Street Journal • Apr. 11, 2026

Three Turkish nationals, including a serviceman, and three Qatari military personnel were killed when a helicopter crashed in Qatar's territorial waters, the Gulf country's defence ministry said.

From Barron's • Mar. 22, 2026

Also, CNN reported that 38 crew members were rescued after a suspected Iranian attack set two foreign tankers ablaze in Iraqi territorial waters, citing the head of Iraq’s ports company.

From MarketWatch • Mar. 11, 2026

Herath said the ship was outside Sri Lanka’s territorial waters.

From The Wall Street Journal • Mar. 4, 2026

Sao Tome is optimistic about the development   of petroleum resources in its territorial waters in the oil-rich   Gulf of Guinea.

From The 2005 CIA World Factbook by United States. Central Intelligence Agency