1 [C] a large important organization that has a particular purpose, for example, a university or bank:
an educational / financial institution * the Smithsonian Institution
2 [C] (usually disapproving) a building where people with special needs are taken care of, for example because they are old or mentally ill:
a mental / penal institution * We want this to be like a home, not an institution.
3 [C] a custom or system that has existed for a long time among a particular group of people:
the institution of marriage * Fish and chips have become a British institution.
4 [U] the act of starting or introducing sth such as a system or a law:
the institution of new safety procedures
5 [C] (informal, humorous) a person who is well known because they have been in a particular place or job for a long time:
You must know him-he's an institution around here!
