From Middle English "pas," from Old French meaning "step," from Latin "passus," a conjugated form of the verb pandere, to spread:
  • a rate of speed or progress ("at a snail's pace")
  • to regulate that speed ("pace yourself")
  • a tempo or gait (particularly a horse's gait in which the legs move in pairs on each side and support the animal alternately on the right and left legs)
  • an example to be followed ("three strokes off the pace")
  • an exhibition of skills ("put through its paces")
  • a manner of walking ("with a measured pace")
  • to measure by pacing ("paced off a ten-yard penalty"). Dict.org quotes the Webster 1913 definition that originally didn't make it to E2 as saying "Ordinarily the pace is estimated at two and one half linear feet; but in measuring distances by stepping, the pace is extended to three feet (one yard) or to three and three tenths feet (one fifth of a rod). The regulation marching pace in the English and United States armies is thirty inches for quick time, and thirty-six inches for double time. The Roman pace (passus) was from the heel of one foot to the heel of the same foot when it next touched the ground, five Roman feet."
  • a device in a loom which maintains tension on the warp fibers while "pacing the web" or winding up the woven cloth on the beam.
  • In architecture, "a broad step or platform; any part of a floor slightly raised above the rest, as around an altar, or at the upper end of a hall"
From the Latin ablative form of of "pac-", "pax," meaning peace or permission
  • a preposition meaning "contrary to the opinions of" ("easiness is a virtue in grammar, pace old-fashioned grammarians -- Philip Howard")

Pace is also:

  • and almost certainly a lot more, but after 50 Google results I got tired of looking at all the organizations using the name.

    Source:
    http://www.m-w.com
    http://www.dict.org/
    http://www.pace.edu
    http://www.paceunion.org
    http://www.planet.edu/~pace/
    http://www.natlpaceassn.org/
    http://www.pacehealth.org.uk/
    http://pace.berkeley.edu/
    http://www.pacefoods.com
    http://www.paceusa.com
    http://www.pace-sci.com/
    http://www.pace.co.uk
    http://www.pace-racing.co.uk
    http://www.pacesportswear.com
    http://www.paceamerican.com
    http://www.pacepros.com/
    http://www.pacegroupexercise.com
    http://www.paceparts.com
    http://www.paceprints.com
    http://www.pacebus.com