overseas territory
Noun
Meaning
A country or smaller territory which politically is either an integral part of - or in some dependent (e.g. colonial) relationship with another state, but is geographically separated from that 'mother state' by the sea, without bordering it or its coastal waters
(law) A more specific status legally defined under a constitution for one or more of the above territories
Source: en.wiktionary.orgExamples
The UK Overseas Territory of Bermuda, for example, had opened an office in Brussels only after the Brexit referendum.
The British Overseas Territory is something of a graveyard for Antarctica's greatest icebergs.