1. an established organization or foundation, especially one dedicated to education, public service, or culture
2. a custom, practice, or behavioral pattern of importance in the life of a community or society
3. a large building where people are cared for or confined, such as a hospital or prison

Examples

• Harvard University is a prestigious educational institution.
• The museum is an important cultural institution in our city.
• Marriage is a fundamental institution in many societies.
• The tradition of afternoon tea is a British institution.
• He was committed to a mental health institution.
• The institution of new policies will take several months.
• Banks are financial institutions that handle money.
• The institution of democracy requires citizen participation.