資料來源 : Webster's Revised Unabridged Dictionary (1913)

Sight \Sight\, n. [OE. sight, si?t, siht, AS. siht, gesiht,
   gesih?, gesieh?, gesyh?; akin to D. gezicht, G. sicht,
   gesicht, Dan. sigte, Sw. sigt, from the root of E. see. See
   {See}, v. t.]
   1. The act of seeing; perception of objects by the eye; view;
      as, to gain sight of land.

            A cloud received him out of their sight. --Acts. i.
                                                  9.

   2. The power of seeing; the faculty of vision, or of
      perceiving objects by the instrumentality of the eyes.

            Thy sight is young, And thou shalt read when mine
            begin to dazzle.                      --Shak.

            O loss of sight, of thee I most complain! --Milton.

   3. The state of admitting unobstructed vision; visibility;
      open view; region which the eye at one time surveys; space
      through which the power of vision extends; as, an object
      within sight.

   4. A spectacle; a view; a show; something worth seeing.

            Moses said, I will now turn aside and see this great
            sight, why the bush is not burnt.     --Ex. iii. 3.

            They never saw a sight so fair.       --Spenser.

   5. The instrument of seeing; the eye.

            Why cloud they not their sights?      --Shak.

   6. Inspection; examination; as, a letter intended for the
      sight of only one person.

   7. Mental view; opinion; judgment; as, in their sight it was
      harmless. --Wake.

            That which is highly esteemed among men is
            abomination in the sight of God.      --Luke xvi.
                                                  15.

   8. A small aperture through which objects are to be seen, and
      by which their direction is settled or ascertained; as,
      the sight of a quadrant.

            Thier eyes of fire sparking through sights of steel.
                                                  --Shak.

   9. A small piece of metal, fixed or movable, on the breech,
      muzzle, center, or trunnion of a gun, or on the breech and
      the muzzle of a rifle, pistol, etc., by means of which the
      eye is guided in aiming. --Farrow.

   10. In a drawing, picture, etc., that part of the surface, as
       of paper or canvas, which is within the frame or the
       border or margin. In a frame or the like, the open space,
       the opening.

   11. A great number, quantity, or sum; as, a sight of money.
       [Now colloquial]

   Note: Sight in this last sense was formerly employed in the
         best usage. ``A sight of lawyers.'' --Latimer.

               A wonder sight of flowers.         --Gower.

   {At sight}, as soon as seen, or presented to sight; as, a
      draft payable at sight: to read Greek at sight; to shoot a
      person at sight.

   {Front sight} (Firearms), the sight nearest the muzzle.

   {Open sight}. (Firearms)
       (a) A front sight through which the objects aimed at may
           be seen, in distinction from one that hides the
           object.
       (b) A rear sight having an open notch instead of an
           aperture.

   {Peep sight}, {Rear sight}. See under {Peep}, and {Rear}.

   {Sight draft}, an order, or bill of exchange, directing the
      payment of money at sight.

   {To take sight}, to take aim; to look for the purpose of
      directing a piece of artillery, or the like.

   Syn: Vision; view; show; spectacle; representation;
        exhibition.

資料來源 : WordNet®

open sight
     n : rear gunsight having an open notch instead of a peephole or
         telescope