资料来源 : Webster's Revised Unabridged Dictionary (1913)

Shear \Shear\, n. [AS. sceara. See {Shear}, v. t.]
   1. A pair of shears; -- now always used in the plural, but
      formerly also in the singular. See {Shears}.

            On his head came razor none, nor shear. --Chaucer.

            Short of the wool, and naked from the shear.
                                                  --Dryden.

   2. A shearing; -- used in designating the age of sheep.

            After the second shearing, he is a two-shear ram; .
            . . at the expiration of another year, he is a
            three-shear ram; the name always taking its date
            from the time of shearing.            --Youatt.

   3. (Engin.) An action, resulting from applied forces, which
      tends to cause two contiguous parts of a body to slide
      relatively to each other in a direction parallel to their
      plane of contact; -- also called {shearing stress}, and
      {tangential stress}.

   4. (Mech.) A strain, or change of shape, of an elastic body,
      consisting of an extension in one direction, an equal
      compression in a perpendicular direction, with an
      unchanged magnitude in the third direction.

   {Shear blade}, one of the blades of shears or a shearing
      machine.

   {Shear hulk}. See under {Hulk}.

   {Shear steel}, a steel suitable for shears, scythes, and
      other cutting instruments, prepared from fagots of
      blistered steel by repeated heating, rolling, and tilting,
      to increase its malleability and fineness of texture.

Shear steel \Shear steel\
   See under {Shear}.