Definitions of imperial:

• noun:   a piece of luggage carried on top of a coach
• noun:   a small tufted beard worn by Emperor Napoleon III
• adjective:   belonging to or befitting a supreme ruler

  Example: "Golden age of imperial splendor"

• adjective:   befitting or belonging to an emperor or empress

  Example: "Imperial palace"

• adjective:   relating to or associated with an empire

  Example: "Imperial colony"

• name:  A surname (very rare: popularity rank in the U.S.: #26447)