enclave

Etymology

Borrowed from French enclave, from Middle French enclave (“enclave”), deverbal of enclaver (“to inclose”), from Old French enclaver (“to inclose, lock in”), from Vulgar Latin *inclāvāre (“to lock in”), from in + Latin clavis (“key”) or clavus (“nail, bolt”). Compare inlock.

noun

1. A political, cultural or social entity or part thereof that is completely surrounded by another.
   The republic of San Marino is an enclave of Italy.
   The streets around Union Square form a Protestant enclave within an otherwise Catholic neighbourhood.
2. A group that is set off from a larger population by its characteristic or behavior.
   ...it tends to make marriage itself a lifestyle enclave.
   What is unbearable, in fact, is the feeling, 13 years after 9/11, that America has been chasing its tail; that, in some whack-a-mole horror show, the quashing of a jihadi enclave here only spurs the sprouting of another there; that the ideology of Al Qaeda is still reverberating through a blocked Arab world whose Sunni-Shia balance (insofar as that went) was upended by the American invasion of Iraq. 17 November 2014, Roger Cohen, “The horror! The horror! The trauma of ISIS [print version: International New York Times, 18 November 2014, p. 9]”, in The New York Times
3. (computing) An isolated portion of an application's address space, such that data in an enclave can only be accessed by code in the same enclave.
   When an enclave spans a system boundary in a sysplex, it is called a multisystem enclave. 2010, Mike Ebbers, Dino Tonelli, Jason Arnold, Co-locating Transactional and Data Warehouse Workloads on System z, page 245

verb

1. (transitive) To enclose within a foreign territory.