clannishly

from WordNet (r) 3.0 (2006)

clannishly
    adv 1: in a clannish manner; "these four friends always act
           clannishly, and don't let us participate in their
           activities" [syn: {clannishly}, {cliquishly}]

from The Collaborative International Dictionary of English v.0.48

Clannish \Clan"nish\, a.
   Of or pertaining to a clan; closely united, like a clan;
   disposed to associate only with one's clan or clique;
   actuated by the traditions, prejudices, habits, etc., of a
   clan. -- {Clan"nish*ly}, adv. -- {clan"nish*ness}, n.
   [1913 Webster]