in·sti·tu·tion 
(ĭn′stĭ-tshən, -ty-)
(ĭn′stĭ-tshən, -ty-)n.
1. The act of instituting: the institution of reforms.
2.
a. A custom, practice, relationship, or behavioral pattern of importance in the life of a community or society: the institutions of marriage and the family.
b. Informal One long associated with a specified place, position, or function.
3.
a. An established organization or foundation, especially one dedicated to education, public service, or culture.
b. A building or complex of buildings housing such an organization.
c. A building or complex of buildings housing people who need special services, such as orphans or people with mental disabilities.