Source : Webster's Revised Unabridged Dictionary (1913)

Stirrup \Stir"rup\, n. [OE. stirop, AS. stigr[=a]p; st[=i]gan to
   mount, ascend + r[=a]p a rope; akin to G. stegreif a stirrup.
   [root]164. See {Sty}, v. i., and {Rope}.]
   1. A kind of ring, or bent piece of metal, wood, leather, or
      the like, horizontal in one part for receiving the foot of
      a rider, and attached by a strap to the saddle, -- used to
      assist a person in mounting a horse, and to enable him to
      sit steadily in riding, as well as to relieve him by
      supporting a part of the weight of the body.

            Our host upon his stirpoes stood anon. --Chaucer.

   2. (Carp. & Mach.) Any piece resembling in shape the stirrup
      of a saddle, and used as a support, clamp, etc. See
      {Bridle iron}.

   3. (Naut.) A rope secured to a yard, with a thimble in its
      lower end for supporting a footrope. --Totten.

   {Stirrup bone} (Anat.), the stapes.

   {Stirrup cup}, a parting cup taken after mounting.

   {Stirrup iron}, an iron stirrup.

   {Stirrup leather}, or {Stirrup strap}, the strap which
      attaches a stirrup to the saddle. See {Stirrup}, 1.

Source : WordNet®

stirrup iron
     n : support consisting of metal loops into which rider's feet go
         [syn: {stirrup}]