Synonyms for Clannish (same or very similar meaning)
WordNet sense 1 (united or combined):
joint
WordNet sense 2 (befitting or characteristic of those who incline to social exclusiveness and who rebuff the advances of people considered inferior):
cliquish, snobbish, snobby, clubby
WordNet sense 3 (confined to particular persons or groups or providing privacy):
private
From the ODE community, based on WordNet
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