befitting or characteristic of those who inclined to social exclusiveness and who rebuff the advances of people considered inferior
If you describe an institution or a group of people as clubby, you mean that all the people in it are friendly with each other and do not welcome other people in. Politics is clubby, careerist, and cynical = cliquey. a clubby place is where everyone is very friendly to each other, but people who are outside their group are not very welcome