Source : Webster's Revised Unabridged Dictionary (1913)

Shadow \Shad"ow\ (sh[a^]d"[-o]), n. [Originally the same word as
   shade. [root]162. See {Shade}.]
   1. Shade within defined limits; obscurity or deprivation of
      light, apparent on a surface, and representing the form of
      the body which intercepts the rays of light; as, the
      shadow of a man, of a tree, or of a tower. See the Note
      under {Shade}, n., 1.

   2. Darkness; shade; obscurity.

            Night's sable shadows from the ocean rise. --Denham.

   3. A shaded place; shelter; protection; security.

            In secret shadow from the sunny ray, On a sweet bed
            of lilies softly laid.                --Spenser.

   4. A reflected image, as in a mirror or in water. --Shak.

   5. That which follows or attends a person or thing like a
      shadow; an inseparable companion; hence, an obsequious
      follower.

            Sin and her shadow Death.             --Milton.

   6. A spirit; a ghost; a shade; a phantom. ``Hence, horrible
      shadow!'' --Shak.

   7. An imperfect and faint representation; adumbration;
      indistinct image; dim bodying forth; hence, mystical
      representation; type.

            The law having a shadow of good things to come.
                                                  --Heb. x. 1.

            [Types] and shadows of that destined seed. --Milton.

   8. A small degree; a shade. ``No variableness, neither shadow
      of turning.'' --James i. 17.

   9. An uninvited guest coming with one who is invited. [A
      Latinism] --Nares.

            I must not have my board pastered with shadows That
            under other men's protection break in Without
            invitement.                           --Massinger.

   {Shadow of death}, darkness or gloom like that caused by the
      presence or the impending of death. --Ps. xxiii. 4.

Shadow \Shad"ow\, v. t. [imp. & p. p. {Shadowed}; p. pr. & vb.
   n. {Shadowing}.] [OE. shadowen, AS. sceadwian. See {adow},
   n.]
   1. To cut off light from; to put in shade; to shade; to throw
      a shadow upon; to overspead with obscurity.

            The warlike elf much wondered at this tree, So fair
            and great, that shadowed all the ground. --Spenser.

   2. To conceal; to hide; to screen. [R.]

            Let every soldier hew him down a bough. And bear't
            before him; thereby shall we shadow The numbers of
            our host.                             --Shak.

   3. To protect; to shelter from danger; to shroud.

            Shadowing their right under your wings of war.
                                                  --Shak.

   4. To mark with gradations of light or color; to shade.

   5. To represent faintly or imperfectly; to adumbrate; hence,
      to represent typically.

            Augustus is shadowed in the person of [AE]neas.
                                                  --Dryden.

   6. To cloud; to darken; to cast a gloom over.

            The shadowed livery of the burnished sun. --Shak.

            Why sad? I must not see the face O love thus
            shadowed.                             --Beau. & Fl.

   7. To attend as closely as a shadow; to follow and watch
      closely, especially in a secret or unobserved manner; as,
      a detective shadows a criminal.

Source : WordNet®

shadow
     v 1: follow, usually without the person's knowledge; "The police
          are shadowing her"
     2: cast a shadow over [syn: {shade}, {shade off}]
     3: make appear small by comparison; "This year's debt dwarves
        that of last year" [syn: {overshadow}, {dwarf}]

shadow
     n 1: shade within clear boundaries
     2: an unilluminated area; "he moved off into the darkness"
        [syn: {darkness}, {dark}]
     3: something existing in perception only; "a ghostly apparition
        at midnight" [syn: {apparition}, {phantom}, {phantasm}, {phantasma}]
     4: a premonition of something adverse; "a shadow over his
        happiness"
     5: an indication that something has been present; "there wasn't
        a trace of evidence for the claim"; "a tincture of
        condescension" [syn: {trace}, {vestige}, {tincture}]
     6: refuge from danger or observation; "he felt secure in his
        father's shadow"
     7: a dominating and pervasive presence; "he received little
        recognition working in the shadow of his father"
     8: a spy employed to follow someone and report their movements
        [syn: {tail}, {shadower}]
     9: an inseparable companion; "the poor child was his mother's
        shadow"

Source : Free On-Line Dictionary of Computing

SHADOW
     
         A {syntax}-directed {compiler} written by Barnett
        and Futrelle in 1962.  It was the predecessor to {SNOBOL}(?)
     
        [Sammet 1969, p. 448, 605].
     
        (1995-01-16)