Noun
1. the act of forming something;
"the constitution of a PTA group last year""it was the establishment of his reputation""he still remembers the organization of the club"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""the governance of an association is responsible to its members""he quickly became recognized as a member of the establishment"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