institution

noun

1. an organization founded and united for a specific purpose
2. an establishment consisting of a building or complex of buildings where an organization for the promotion of some cause is situated
3. a custom that for a long time has been an important feature of some group or society"the institution of marriage"
4. the act of starting something for the first time; introducing something new"she looked forward to her initiation as an adult"
5. a hospital for mentally incompetent or unbalanced person