PROJEC'TION, n. [L. projectio.] The act of throwing or shooting forward.

1. A jutting out; extension beyond something else.

2. The act of scheming; plan; scheme; design of something to be executed.

3. Plan; delineation; the representation of something; as the projection of the sphere, is a representation of the circles on the surface of the sphere. There are three principal points of projection; the stereographic, in which the eye is supposed to be placed on the surface of the sphere; the orthographic, in which the eye is supposed to be at an infinite distance; and the gnomonic, in which the eye is placed in the center of the sphere.

In perspective, projection denotes the appearance or representation of an object on the perspective plane.

4. In alchimy, the casting of a certain powder, called powder of projection, into a crucible or other vessel full of some prepared metal or other matter, which is to be thereby transmuted into gold.