An Institution is a humanly devised constraints that structures political, economic and social interactions.
An Institution is a group of people united by common interest, endowed by material equipment, following rules of their tradition or agreement (charter) and contributing to the work of culture as a whole.
An Institution is a system of beliefs and practices (such as, say private property) in which all members know and expect their own role, the roles of others, and the accompanying attitudes, but all also know that virtually everyone else knows the roles and expects them to act accordingly.
An Institution is a structured social practice that has a broad spatial and temporal extension.
An Institution is a social entity such as as family, marriage, family, government, educational, legal, penal, heart, religious, service industry.
An Institution is a pattern of interaction among humans that is regularized and seen as meaningful.
The Institution is (as, for example, the family, the organization, the economy) an ordered network of heterogeneous materials whose resistance has been overcome.

The Institution is always possessed of the pathetic megalomania of the computer whose whole vision of the world is its own program.