exclave

noun

territory legally or politically attached to a main territory with which it is not physically contiguous because of surrounding alien territory

Wiktionary

Pronunciation: /ˈɛkskleɪv/

noun

Etymology: Etymology tree Proto-Indo-European *h₁éǵʰs Proto-Italic *eks Latin ex Latin ex-der. Middle French ex-bor. Middle English ex- English ex- English (en)clave English exclave From ex- + (en)clave.

A portion of a country's territory not connected to the main part.
“Alaska and Kaliningrad are both examples of exclaves.”
“While there has never been a macronational bedroom nation, some exclaves have been barely larger.”
A detached part of an organ, as of the pancreas, thyroid (accessory thyroids), or other gland.

verb

To separate a region in a way that turns it into an exclave.