Definitions of spur:

• noun:   a sharp prod fixed to a rider's heel and used to urge a horse onward

  Example: "Cowboys know not to squat with their spurs on"

• noun:   tubular extension at the base of the corolla in some flowers
• noun:   any pointed projection
• noun:   a railway line connected to a trunk line
• noun:   a verbalization that encourages you to attempt something
• verb:   incite or stimulate

  Example: "The Academy was formed to spur research"

• verb:   goad with spurs

  Example: "The rider spurred his horse"

• verb:   equip with spurs

  Example: "Spur horses"

• verb:   strike with a spur
• verb:   give heart or courage to