1.nounThe act of establishing; a ratifying or ordaining; settlement; confirmation.
"Since their establishment of the company in 1984, they have grown into a global business."
2.nounThe state of being established, founded, etc.; fixed state.
"The firm celebrated twenty years since their establishment by updating their look."
3.nounThat which is established; as a form of government, a permanent organization, business or force, or the place where one is permanently fixed for residence.
"Exposing the shabby parts of the establishment."
4.noun(usually with "the") The ruling class or authority group in a society; especially, an entrenched authority dedicated to preserving the status quo. Also Establishment.
"It's often necessary to question the establishment to get things done."
5.nounThe number of staff required to run a department or organisation (often used in the context of healthcare and other public services).
"The cancer department has an establishment of 10 doctors and 30 nurses."