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.