Ex-pān'sion, n.
(eks-pān'shun), n. [Lat. expansio, Fr. & Sp. expansion, It. espansione.]
Sense 1. The act of expanding or spreading out, or the condition of being expanded; dilatation; distention; enlargement.
Sense 2. That which is expanded; expanse; extended surface; as, the expansion of a sheet or of a lake; the expansion of fluids or metals. “The starred expansion of the skies.” Beattie.
Sense 3. Extension of space; space; room; immensity.
Lost in expansion, void and infinite. Blackmore.
Sense 4. (Com.) Enlargement or extension of business transactions; especially, increase of the circulation of bank notes.
Sense 5. (Math.) The developed result of an indicated operation; as, the expansion of (a + b)² is a² + 2ab + b². Math. Dict.
Sense 6. (Steam-eng.) The operation of steam in a cylinder after its communication with the boiler has been cut off, by which it produces a pressure on the piston, varying inversely as the increasing space it fills, as the piston retreats before it.