1.the act of forming something;
the constitution of a PTA group last year
2.an organization founded and united for a specific purpose
3.the persons (or committees or departments etc.) who make up a body for the purpose of administering something;
he claims that the present administration is corrupt
4.a public or private structure (business or governmental or educational) including buildings and equipment for business or residence
5.any large organization
6.(ecology) the process by which a plant or animal becomes established in a new habitat
7.the cognitive process of establishing a valid proof