1. [n]  the formation of a mental image of something that is not perceived as real and is not present to the senses; "popular imagination created a world of demons"; "imagination reveals what the world could be"
2. [n]  the ability to see; the faculty of vision
3. [n]  the perceptual experience of seeing; "the runners emerged from the trees into his clear vision"; "he had a visual sensation of intense light"
4. [n]  a vivid mental image; "he had a vision of his own death"
5. [n]  a religious or mystical experience of a supernatural appearance; "he had a vision of the Virgin Mary"

1. \Vi"sion\, n. [OE. visioun, F. vision, fr. L. visio, from
   videre, visum, to see: akin to Gr. ? to see, ? I know, and E.
   wit. See {Wit}, v., and cf. {Advice}, {Clairvoyant}, {Envy},
   {Evident}, {Provide}, {Revise}, {Survey}, {View}, {Visage},
   {Visit}.]
   1. The act of seeing external objects; actual sight.
            Faith here is turned into vision there. --Hammond.
   2. (Physiol.) The faculty of seeing; sight; one of the five
      senses, by which colors and the physical qualities of
      external objects are appreciated as a result of the
      stimulating action of light on the sensitive retina, an
      expansion of the optic nerve.
   3. That which is seen; an object of sight. --Shak.
   4. Especially, that which is seen otherwise than by the
      ordinary sight, or the rational eye; a supernatural,
      prophetic, or imaginary sight; an apparition; a phantom; a
      specter; as, the visions of Isaiah.
            The baseless fabric of this vision.   --Shak.
            No dreams, but visions strange.       --Sir P.
                                                  Sidney.
   5. Hence, something unreal or imaginary; a creation of fancy.
      --Locke.
   {Arc of vision} (Astron.), the arc which measures the least
      distance from the sun at which, when the sun is below the
      horizon, a star or planet emerging from his rays becomes
      visible.
   {Beatific vision} (Theol.), the immediate sight of God in
      heaven.
   {Direct vision} (Opt.), vision when the image of the object
      falls directly on the yellow spot (see under {Yellow});
      also, vision by means of rays which are not deviated from
      their original direction.
   {Field of vision}, field of view. See under {Field}.
   {Indirect vision} (Opt.), vision when the rays of light from
      an object fall upon the peripheral parts of the retina.
   {Reflected vision}, or {Refracted vision}, vision by rays
      reflected from mirrors, or refracted by lenses or prisms,
      respectively.
   {Vision purple}. (Physiol.) See {Visual purple}, under
      {Visual}.
   

2. \Vi"sion\, v. t. [imp. & p. p. {Visioned}; p. pr. & vb.
   n. {Visioning}.]
   To see in a vision; to dream.
         For them no visioned terrors daunt, Their nights no
         fancied specters haunt.                  --Sir W.
                                                  Scott.
   

(Luke 1:22), a vivid apparition, not a dream (comp. Luke 24:23; Acts 26:19; 2 Cor. 12:1).