0 behaviour that is friendly and helpful only to other people in your group, but not to people outside the group:
There have been complaints about the clannishness and secretiveness of the Church.
There was a harmful clannishness between the different nationalities at the club.
The newcomers became resentful of the local population's almost tribal clannishness.
The O'Dwyers had that clannishness that made them stick together in spite of politics.
