institution n1 : the act of instituting
2 : a significant practice, relationship, or organization in a society or culture [the of marriage]
3 : an established organization or corporation esp. of a public character
: a facility for the treatment or training of persons with mental deficiencies
Source: Merriam-Webster's Dictionary of Law ©1996. Merriam-Webster, Incorporated. Published under license with Merriam-Webster, Incorporated.