Definitions of progressive:

• noun:   a tense of verbs used in describing action that is on-going
• noun:   a person who favors a political philosophy of progress and reform and the protection of civil liberties
• adjective:   favoring or promoting progress

  Example: "Progressive schools"

• adjective:   (of taxes) adjusted so that the rate increases as the amount increases
• adjective:   gradually advancing in extent
• adjective:   advancing in severity

  Example: "Progressive paralysis"

• adjective:   favoring or promoting reform (often by government action)