Source : Webster's Revised Unabridged Dictionary (1913)

   2. That which goads to action; an incitement.

            Fame is the spur that the clear spirit doth raise
            (That last infirmity of noble mind) To scorn
            delights and live laborious days.     --Milton.

   3. Something that projects; a snag.

   4. One of the large or principal roots of a tree. --Shak.

   5. (Zo["o]l.) Any stiff, sharp spine, as on the wings and
      legs of certain burds, on the legs of insects, etc.;
      especially, the spine on a cock's leg.

   6. A mountain that shoots from any other mountain, or range
      of mountains, and extends to some distance in a lateral
      direction, or at right angles.

   7. A spiked iron worn by seamen upon the bottom of the boot,
      to enable them to stand upon the carcass of a whale, to
      strip off the blubber.

   8. (Carp.) A brace strengthening a post and some connected
      part, as a rafter or crossbeam; a strut.

   9. (Arch.)
      (a) The short wooden buttress of a post.
      (b) A projection from the round base of a column,
          occupying the angle of a square plinth upon which the
          base rests, or bringing the bottom bed of the base to
          a nearly square form. It is generally carved in
          leafage.

   10. (Bot.)
       (a) Any projecting appendage of a flower looking like a
           spur. --Gray.
       (b) Ergotized rye or other grain. [R.]

   11. (Fort.) A wall that crosses a part of a rampart and joins
       to an inner wall.

   12. (Shipbuilding)
       (a) A piece of timber fixed on the bilge ways before
           launching, having the upper ends bolted to the
           vessel's side.
       (b) A curved piece of timber serving as a half to support
           the deck where a whole beam can not be placed.

   {Spur fowl} (Zo["o]l.), any one of several species of Asiatic
      gallinaceous birds of the genus {Galloperdix}, allied to
      the jungle fowl. The males have two or more spurs on each
      leg.

   {Spur gear} (Mach.), a cogwheel having teeth which project
      radially and stand parallel to the axis; a spur wheel.

   {Spur gearing}, gearing in which spur gears are used. See
      under {Gearing}.

   {Spur pepper}. (Bot.) See the Note under {Capsicum}.

   {Spur wheel}. Same as {Spur gear}, above.

Gearing \Gear"ing\, n.
   1. Harness.

   2. (Mach.) The parts by which motion imparted to one portion
      of an engine or machine is transmitted to another,
      considered collectively; as, the valve gearing of
      locomotive engine; belt gearing; esp., a train of wheels
      for transmitting and varying motion in machinery.

   {Frictional gearing}. See under {Frictional}.

   {Gearing chain}, an endless chain transmitted motion from one
      sprocket wheel to another. See Illust. of {Chain wheel}.
      

   {Spur gearing}, gearing in which the teeth or cogs are ranged
      round either the concave or the convex surface (properly
      the latter) of a cylindrical wheel; -- for transmitting
      motion between parallel shafts, etc.