Source : Webster's Revised Unabridged Dictionary (1913)

Projection \Pro*jec"tion\, n. [L. projectio: cf. F. projection.]
   1. The act of throwing or shooting forward.

   2. A jutting out; also, a part jutting out, as of a building;
      an extension beyond something else.

   3. The act of scheming or planning; also, that which is
      planned; contrivance; design; plan. --Davenant.

   4. (Persp.) The representation of something; delineation;
      plan; especially, the representation of any object on a
      perspective plane, or such a delineation as would result
      were the chief points of the object thrown forward upon
      the plane, each in the direction of a line drawn through
      it from a given point of sight, or central point; as, the
      projection of a sphere. The several kinds of projection
      differ according to the assumed point of sight and plane
      of projection in each.

   5. (Geog.) Any method of representing the surface of the
      earth upon a plane.

   {Conical projection}, a mode of representing the sphere, the
      spherical surface being projected upon the surface of a
      cone tangent to the sphere, the point of sight being at
      the center of the sphere.

   {Cylindric projection}, a mode of representing the sphere,
      the spherical surface being projected upon the surface of
      a cylinder touching the sphere, the point of sight being
      at the center of the sphere.

   {Globular}, {Gnomonic}, {Orthographic}, {projection},etc. See
      under {Globular}, {Gnomonic}, etc.

   {Mercator's projection}, a mode of representing the sphere in
      which the meridians are drawn parallel to each other, and
      the parallels of latitude are straight lines whose
      distance from each other increases with their distance
      from the equator, so that at all places the degrees of
      latitude and longitude have to each other the same ratio
      as on the sphere itself.

   {Oblique projection}, a projection made by parallel lines
      drawn from every point of a figure and meeting the plane
      of projection obliquely.

   {Polar projection}, a projection of the sphere in which the
      point of sight is at the center, and the plane of
      projection passes through one of the polar circles.

   {Powder of projection} (Alchemy.), a certain powder cast into
      a crucible or other vessel containing prepared metal or
      other matter which is to be thereby transmuted into gold.
      

   {Projection of a point on a plane} (Descriptive Geom.), the
      foot of a perpendicular to the plane drawn through the
      point.

   {Projection of a straight line of a plane}, the straight line
      of the plane connecting the feet of the perpendiculars let
      fall from the extremities of the given line.

   Syn: See {Protuberance}.

Source : WordNet®

projection
     n 1: a prediction made by extrapolating from past observations
     2: the projection of an image from a film onto a screen
     3: a planned undertaking [syn: {project}]
     4: any structure that branches out from a central support
     5: any solid convex shape that juts out from something
     6: (psychiatry) a defense mechanism by which your own traits
        and emotions are attributed to someone else
     7: the acoustic phenomenon that gives sound a penetrating
        quality; "our ukuleles have been designed to have superior
        sound and projection"; "a prime ingredient of public
        speaking is projection of the voice" [syn: {acoustic
        projection}, {sound projection}]
     8: the representation of a figure or solid on a plane as it
        would look from a particular direction
     9: the act of projecting out from something [syn: {protrusion},
         {jut}, {jutting}]
     10: the act of expelling or projecting or ejecting [syn: {expulsion},
          {ejection}, {forcing out}]

Source : Free On-Line Dictionary of Computing

projection
     
         In domain theory, a {function}, f, which is (a)
        {idempotent}, i.e.  f(f(x))=f(x) and (b) whose result is no
        more defined than its argument.  E.g. F(x)=bottom or F(x)=x.
     
        In {reduction} systems, a function which returns some
        {component} of its argument.  E.g. head, tail, \ (x,y) . x.
        In a {graph reduction} system the function can just return a
        pointer to part of its argument and does not need to build any
        new graph.
     
        (1997-01-29)