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

Rotary \Ro"ta*ry\, a. [L. rota a wheel. See {Roll}, v., and cf.
   {barouche}, {Rodomontade}, {Rou['e]}, {Round}, a., {Rowel}.]
   Turning, as a wheel on its axis; pertaining to, or
   resembling, the motion of a wheel on its axis; rotatory; as,
   rotary motion.

   {Rotary engine}, steam engine in which the continuous
      rotation of the shaft is produced by the direct action of
      the steam upon rotating devices which serve as pistons,
      instead of being derived from a reciprocating motion, as
      in the ordinary engine; a steam turbine; -- called also
      {rotatory engine}.

   {Rotary pump}, a pump in which the fluid is impelled by
      rotating devices which take the place of reciprocating
      buckets or pistons.

   {Rotary shears}, shears, as for cloth, metal, etc., in which
      revolving sharp-edged or sharp-cornered wheels do the
      cutting.

   {Rotary valve}, a valve acting by continuous or partial
      rotation, as in the four-way cock.

Shears \Shears\, n. pl. [Formerly used also in the singular. See
   {Shear}, n., 1.]
   1. A cutting instrument. Specifically:
      (a) An instrument consisting of two blades, commonly with
          bevel edges, connected by a pivot, and working on both
          sides of the material to be cut, -- used for cutting
          cloth and other substances.

                Fate urged the shears, and cut the sylph in
                twain.                            --Pope.
      (b) A similar instrument the blades of which are
          extensions of a curved spring, -- used for shearing
          sheep or skins.
      (c) A shearing machine; a blade, or a set of blades,
          working against a resisting edge.

   2. Anything in the form of shears. Specifically:
      (a) A pair of wings. [Obs.] --Spenser.
      (b) An apparatus for raising heavy weights, and especially
          for stepping and unstepping the lower masts of ships.
          It consists of two or more spars or pieces of timber,
          fastened together near the top, steadied by a guy or
          guys, and furnished with the necessary tackle.
          [Written also {sheers}.]

   3. (Mach.) The bedpiece of a machine tool, upon which a table
      or slide rest is secured; as, the shears of a lathe or
      planer. See Illust. under {Lathe}.

   {Rotary shears}. See under {Rotary}.