The Collaborative International Dictionary of English v.0.48:

Pace \Pace\ (p[=a]s), v. i. [imp. & p. p. Paced (p[=a]st); p.
   pr. & vb. n. Pacing (p[=a]"s[i^]ng).]
   1. To go; to walk; specifically, to move with regular or
      measured steps. "I paced on slowly." --Pope. "With speed
      so pace." --Shak.
      [1913 Webster]

   2. To proceed; to pass on. [Obs.]
      [1913 Webster]

            Or [ere] that I further in this tale pace.
                                                  --Chaucer.
      [1913 Webster]

   3. To move quickly by lifting the legs on the same side
      together, as a horse; to amble with rapidity; to rack.
      [1913 Webster]

   4. To pass away; to die. [Obs.] --Chaucer.
      [1913 Webster]

The Collaborative International Dictionary of English v.0.48:

pacing \pacing\ n.
   the speed at which a composition is to be played.

   Syn: tempo.
        [WordNet 1.5]

WordNet (r) 3.0 (2006):

pacing
    n 1: (music) the speed at which a composition is to be played
         [syn: tempo, pacing]
    2: walking with slow regular strides