EXPANSION
Ex*pan"sion, n. Etym: [L. expansio: cf. F. expansion.]

1. The act of expanding or spreading out; the condition of being expanded; dilation; enlargement.

2. That which is expanded; expanse; extend surface; as the expansion of a sheet or of a lake; the expansion was formed of metal. The starred expansion of the skies. Beattie.

3. Space thought which anything is expanded; also, pure space. Lost in expansion, void and infinite. Blackmore.

4. (Com.)

Defn: Enlargement or extension of business transaction; esp., increase of the circulation of bank notes.

5. (Math.)

Defn: The developed result of an indicated operation; as, the expansion of (a + b)2 is a2 + 2ab + b2.

6. (Steam Ebgine)

Defn: 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.