clannish
From Longman Dictionary of Contemporary Englishclannishclan‧nish /ˈklænɪʃ/ adjective written a group of people who are clannish are very close to each other, and seem unfriendly towards strangers a clannish communityExamples from the Corpusclannish• The sanctity of traditional ownership and lineage are hoisted like clannish flags.• The town had settled to being itself again, sleepy, clannish, introverted.