Definitions of leading:

• noun:   the activity of leading
• noun:   thin strip of metal used to separate lines of type in printing
• adjective:   purposefully formulated to elicit a desired response

  Example: "A leading question"

• adjective:   going or proceeding or going in advance; showing the way

  Example: "We rode in the leading car"

• adjective:   having the leading position or higher score in a contest

  Example: "The leading team in the pennant race"