formation

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

• noun The act or process of forming something or of taking form.
• noun Something formed.
• noun The manner or style in which something is formed; structure.
• noun A specified arrangement or deployment, as of aircraft, troops, or players on a sports team.
• noun Geology A primary unit in the mapping of rock strata, consisting of a set of contemporaneous rocks having the same characteristics and origin.

from The Century Dictionary.

• noun The act or process of forming or making; the operation of composing by the union of materials or elements, or of shaping and giving form; a putting or coming into form: as, the formation of a state or constitution; the formation of ideas or of character.
• noun Disposition of parts or elements; formal structure or arrangement; conformation; configuration: as, the peculiar formation of the heart; a formation of troops in columns, squares, etc.
• noun That which is formed; anything considered as to its form, structure, or arrangement: as, the formation consisted of a mass of incongruous materials. Specifically
• noun In geology, properly, a group or assemblage of rocks, whether stratified or unstratified, having a similar origin or some common physical character.
• noun In the classification of rock-masses as adopted by the United States Geological Survey for cartographic purposes, the cartographic unit, or usually the ultimate rock body separately named and mapped.
• noun In œcol., a plant society or association. See the extract and plant formation.

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

• noun The act of giving form or shape to anything; a forming; a shaping.
• noun The manner in which a thing is formed; structure; construction; conformation; form.
• noun A substance formed or deposited.
• noun Mineral deposits and rock masses designated with reference to their origin
• noun A group of beds of the same age or period.
• noun (Mil.) The arrangement of a body of troops, as in a square, column, etc.

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

• noun Something possessing structure or form.
• noun The act of assembling a group or structure.
• noun geology A rock or face of a mountain.
• noun military A grouping of military units or smaller formations under a command, such as a brigade, division, wing, etc.
• noun military An arrangement of moving troops, ships, or aircraft, such as a wedge, line abreast, or echelon. Often "in formation".
• noun The process of influencing or guiding a person to a deeper understanding of a particular vocation.

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

• noun a particular spatial arrangement
• noun an arrangement of people or things acting as a unit
• noun creation by mental activity
• noun the act of forming or establishing something
• noun natural process that causes something to form
• noun (geology) the geological features of the earth
• noun the act of fabricating something in a particular shape