institution

from The American Heritage® Dictionary of the English Language, 5th Edition.

• noun The act of instituting.
• noun A custom, practice, relationship, or behavioral pattern of importance in the life of a community or society.
• noun Informal One long associated with a specified place, position, or function.
• noun An established organization or foundation, especially one dedicated to education, public service, or culture.
• noun The building or buildings housing such an organization.
• noun A place for the care of persons who are destitute, disabled, or mentally ill.

from The Century Dictionary.

• noun The act of instituting or setting up; establishment; effective ordination: as, the institution of laws or government; the institution of an inquiry.
• noun Establishment in office; in ecclesiastical use, instatement in a spiritual charge; investment with the cure of souls. See installation.
• noun Establishment in learning; instruction.
• noun Established rule or order; a principle of procedure in any relation; custom; more specifically, an established habit of action, or body of related facts, regulating human conduct in the attainment of a social end, and constituting an element in the social organization or civilization of a community: as, government, the family, a language, is an institution.
• noun An established custom or usage, or a characteristic.
• noun An establishment for the promotion of some object; an organized society or body of persons, usually with a fixed place of assemblage and operation, devoted to a special pursuit or purpose: as, an educational institution; a charitable institution; the Smithsonian Institution at Washington.
• noun A system of the elements or rules of any art or science; a treatise or text-book.
• noun Eccles.: The origination of the eucharist, and enactment of its observance, by Christ.
• noun The words used by Christ in instituting the eucharist, in the various forms as recorded in Scripture (Mat. xxvi. 26–28; Mark xiv. 22–24; Luke xxii. 19, 20; 1 Cor. xi. 23–25), or transmitted by tradition; in liturgics, the part of the prayer of consecration of the eucharistic elements in which these words are repeated. Also called more fully the commemoration, recital, or words of institution.
• noun The act by which a bishop commits the cure of souls under himself in a parish within his diocese to a priest as rector or vicar.

from the GNU version of the Collaborative International Dictionary of English.

• noun The act or process of instituting; as: (a) Establishment; foundation; enactment.
• noun obsolete Instruction; education.
• noun (Eccl. Law) The act or ceremony of investing a clergyman with the spiritual part of a benefice, by which the care of souls is committed to his charge.
• noun That which instituted or established.
• noun Established order, method, or custom; enactment; ordinance; permanent form of law or polity.
• noun An established or organized society or corporation; an establishment, especially of a public character, or affecting a community; a foundation; ; also, a building or the buildings occupied or used by such organization.
• noun Anything forming a characteristic and persistent feature in social or national life or habits.
• noun obsolete That which institutes or instructs; a textbook; a system of elements or rules; an institute.

from Wiktionary, Creative Commons Attribution/Share-Alike License.

• noun An established organisation, especially one dedicated to education, public service, culture or the care of the destitute, poor etc.
• noun The building which houses such an organisation.
• noun A custom or practice of a society or community - marriage for example.
• noun informal A person long established with a certain place or position.
• noun The act of instituting.
• noun obsolete That which institutes or instructs; a textbook or system of elements or rules.

from WordNet 3.0 Copyright 2006 by Princeton University. All rights reserved.

• noun an organization founded and united for a specific purpose
• noun the act of starting something for the first time; introducing something new
• noun a custom that for a long time has been an important feature of some group or society
• noun a hospital for mentally incompetent or unbalanced person
• noun an establishment consisting of a building or complex of buildings where an organization for the promotion of some cause is situated