Definitions of span:

• noun:   the distance or interval between two points
• noun:   a unit of length based on the width of the expanded human hand (usually taken as 9 inches)
• noun:   the complete duration of something

  Example: "The job was finished in the span of an hour"

• noun:   the act of sitting or standing astride
• noun:   a structure that allows people or vehicles to cross an obstacle such as a river or canal or railway etc.
• noun:   two items of the same kind
• verb:   to cover or extend over an area or time period

  Example: "Rivers traverse the valley floor, The parking lot spans 3 acres"

• name:  A surname (rare: 1 in 100000 families; popularity rank in the U.S.: #18438)