sonderbund
/ˈzɒndərbʌnd/Definitions
1. noun
A small, often private, school or educational institution, especially in Switzerland, that is not part of the public education system.
“The Swiss government struggled to regulate the numerous sonderbunds operating in the country.”
2. noun
A group of people united by a shared interest or activity.
“The sonderbund of artists in the city came together to create a mural in the town square.”