Webster's Revised Unabridged Dictionary · 1913

Outline

Outline , noun

1.
(a) The line which marks the outer limits of an object or figure; the exterior line or edge; contour.
(b)
In art: A line drawn by pencil, pen, graver, or the like, by which the boundary of a figure is indicated.
(c)
A sketch composed of such lines; the delineation of a figure without shading.
Painters, by their outlines, colors, lights, and shadows, represent the same in their pictures. — Dryden
2.
Figuratively: A sketch of any scheme; a preliminary or general indication of a plan, system, discourse, course of thought, etc.; as, the outline of a speech.
But that larger grief... Is given in outline and no more. — Tennyson

Outline , transitive verb

1.
To draw the outline of.
2.
Figuratively: To sketch out or indicate as by an outline; to create a general framework of (a plan, system, discourse, course of thought), for which the details need to be added; as, to outline an argument or a campaign.