Expansion

Part of speech: noun (n.)

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

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

6. 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.

7. The enlargement of the ship mathematically from a model or drawing to the full or building size, in the process of construction. Ham. Nav. Encyc.

8. A clamp for holding a locomotive frame to the boiler while allowing lengthwise motion. -- Expansion valve (Steam Engine), a cut-off valve, to shut off steam from the cylinder before the end of each stroke.