Definitions of gallop:

• noun:   a fast gait of a horse; a two-beat stride during which all four legs are off the ground simultaneously
• verb:   ride at a galloping pace

  Example: "He was galloping down the road"

• verb:   cause to move at full gallop

  Example: "Did you gallop the horse just now?"

• verb:   go at galloping speed

  Example: "The horse was galloping along"

• name:  A surname (rare: 1 in 100000 families; popularity rank in the U.S.: #13522)