Definitions of mobile:

• noun:   sculpture suspended in midair whose delicately balanced parts can be set in motion by air currents
• noun:   a port in southwestern Alabama on Mobile Bay
• noun:   a river in southwestern Alabama; flows into Mobile Bay
• adjective:   moving or capable of moving readily (especially from place to place)

  Example: "A mobile missile system"

• adjective:   having transportation available
• adjective:   (of groups of people) tending to travel and change settlements frequently

  Example: "A restless mobile society"

• adjective:   capable of changing quickly from one state or condition to another

  Example: "A highly mobile face"

• adjective:   affording change (especially in social status)

  Example: "Upwardly mobile"