Source : Webster's Revised Unabridged Dictionary (1913)

Single-foot \Sin"gle-foot`\, n.
   An irregular gait of a horse; -- called also {single-footed
   pace}. See {Single}, v. i.

         Single-foot is an irregular pace, rather rare,
         distinguished by the posterior extremities moving in
         the order of a fast walk, and the anterior extremities
         in that of a slow trot.                  --Stillman
                                                  (The Horse in
                                                  Motion.)

Single-foot \Sin"gle-foot`\, v. i.
   To proceed by means of the single-foot, as a horse or other
   quadruped. -- {Sin"gle-foot`er}, n.

Source : WordNet®

single-foot
     n : a rapid gait of a horse in which each foot strikes the
         ground separately [syn: {rack}]
     v : go at a rack; "the horses single-footed" [syn: {rack}]