high sea

noun
1.
the sea or ocean beyond the three-mile limit or territorial waters of a country.
2.
Usually, high seas.
  1. the open, unenclosed waters of any sea or ocean; common highway.
  2. Law. the area within which transactions are subject to court of admiralty jurisdiction.
Origin
before 1100; Middle English; Old English hēah-sǣ
Related forms
high-sea, adjective
British Dictionary definitions for high seas

high seas

plural noun
1.
(sometimes sing) the open seas of the world, outside the jurisdiction of any one nation
Idioms and Phrases with high seas

high seas

Open waters of an ocean or sea, beyond the territorial jurisdiction of a country. For example, Commercial fishermen are being forced to go out on the high seas in order to make a living. [ c. 1100 ]