Definitions of pace:

• noun:   a step in walking or running
• noun:   the relative speed of progress or change

  Example: "He lived at a fast pace"

• noun:   the rate of moving (especially walking or running)
• noun:   a unit of length equal to 3 feet; defined as 91.44 centimeters; originally taken to be the average length of a stride
• noun:   the distance covered by a step

  Example: "He stepped off ten paces from the old tree and began to dig"

• noun:   the rate of some repeating event
• verb:   go at a pace

  Example: "The horse paced"

• verb:   measure (distances) by pacing
• verb:   regulate or set the pace of

  Example: "Pace your efforts"

• verb:   walk with slow or fast paces

  Example: "He paced up and down the hall"

• name:  A surname (common: 1 in 5882 families; popularity rank in the U.S.: #681)