There are multiple definitions - click on the translation that matches your context.

Anstalt des öffentlichen Rechts

Substantiv

partial

institution

noun

Definitions of institution

English

a long-established law or custom

Critics have attacked the plans as an assault on the institution of marriage.

English

an established society or official organization with an important role in society (eg a school or a hospital); a large company

The Catholic Church, based in Rome and headed by the Pope, is the oldest institution in the western world.

English

the action of instituting something

I am advised that there is sufficient admissible evidence to support the institution of criminal proceedings.