Definition of "Establishment" :

noun: the act of forming or establishing something

"It was the establishment of his reputation."

noun: a public or private structure (business or governmental or educational) including buildings and equipment for business or residence

noun: the cognitive process of establishing a valid proof

noun: an organization founded and united for a specific purpose

noun: any large organization

noun: the persons (or committees or departments etc.) who make up a body for the purpose of administering something

"He quickly became recognized as a member of the establishment."

noun: (ecology) the process by which a plant or animal becomes established in a new habitat