expansion

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

• noun The act or process of expanding.
• noun The state of being expanded.
• noun An expanded part.
• noun A product of expanding.
• noun The extent or amount by which something has expanded.
• noun A quantity written in an extended form, such as in a sum or product of terms.
• noun The process of obtaining this form.
• noun An expanse.
• noun A period of increased economic or business activity.

from The Century Dictionary.

• noun The act of expanding.
• noun The act of extending or distending, or of increasing in extent, size, bulk, amount, etc.
• noun The state of being expanded; enlargement; distention; dilatation; increase of extent, size, bulk, amount, etc.
• noun Specifically The increase in bulk of steam in the cylinder of an engine when its communication with the boiler is cut off, in which case its pressure on the piston retreating before it is in inverse ratio to the space it fills.
• noun A part which constitutes an increase or in which the expanding occurs; specifically, in entomology, a flat projection of a margin, generally lateral: as, a frontal expansion covering the base of the antennæ.
• noun Extension or spread of space; extent in general; hence, wide extent; immensity.
• noun In mathematics, the development at length of an expression indicated in a contracted form, especially by means of the distributive principle.
• noun In ship-building, a drawing in which a curved or warped surface, as a ship's outside plating or a longitudinal, is laid out or expanded on a plane surface by conventional methods to show approximately the true relations and dimensions of the parts.

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

• noun The act of expanding or spreading out; the condition of being expanded; dilation; enlargement.
• noun That which is expanded; expanse; extend surface.
• noun Space through which anything is expanded; also, pure space.
• noun (Economics & Commmerce) an increase in the production of goods and services over time, and in the volume of business transactions, generally associated with an increase in employment and an increase in the money supply. Opposite of contraction.
• noun (Math.) The developed result of an indicated operation.
• noun (Steam Engine) The operation of steam in a cylinder after its communication with the boiler has been cut off, by which it continues to exert pressure upon the moving piston.
• noun (Nav. Arch.) The enlargement of the ship mathematically from a model or drawing to the full or building size, in the process of construction.
• noun an enlarged or extended version of something, such as a writing or discourse.
• noun Colloq. or jargon an expansion joint. See below.
• noun a curve the coördinates of which show the relation between the pressure and volume of expanding gas or vapor; esp. (Steam engine), that part of an indicator diagram which shows the declining pressure of the steam as it expands in the cylinder.
• noun (Steam Engine) a cut-off gear. See Illust. of Link motion.
• noun one that is regulated by the governor, and varies the supply of steam to the engine with the demand for power.
• noun one that always operates at the same fixed point of the stroke.
• noun (Mech. & Engin.) a strip of compressible material placed at intervals between blocks of poured concrete, as in roads or sidewalks.
• noun (Steam Engine) a cut-off valve, to shut off steam from the cylinder before the end of each stroke.

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

• noun The act or process of expanding.
• noun The fractional change in unit length per unit length per unit temperature change.
• noun A new addition.
• noun A product to be used with a previous product.

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

• noun a discussion that provides additional information
• noun the act of increasing (something) in size or volume or quantity or scope
• noun a function expressed as a sum or product of terms
• noun adding information or detail