Definitions of outline:

• noun:   a schematic or preliminary plan
• noun:   a sketchy summary of the main points of an argument or theory
• noun:   the line that appears to bound an object
• verb:   describe roughly or briefly or give the main points or summary of

  Example: "Sketch the outline of the book"

• verb:   draw up an outline or sketch for something
• verb:   trace the shape of