The Collaborative International Dictionary of English v.0.48:

Outline \Out"line`\, v. t. [imp. & p. p. Outlined; p. pr. &
   vb. n. Outlining.]
   1. To draw the outline of.
      [1913 Webster]

   2. Fig.: 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.
      [1913 Webster]

The Collaborative International Dictionary of English v.0.48:

Outline \Out"line`\, n.
   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.
          [1913 Webster]

                Painters, by their outlines, colors, lights, and
                shadows, represent the same in their pictures.
                                                  --Dryden.
          [1913 Webster]

   2. Fig.: 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.
      [1913 Webster]

            But that larger grief . . .
            Is given in outline and no more.      --Tennyson.
      [1913 Webster]

   Syn: Sketch; draught; delineation. See Sketch.
        [1913 Webster]

WordNet (r) 3.0 (2006):

outline
    n 1: the line that appears to bound an object [syn: outline,
         lineation]
    2: a sketchy summary of the main points of an argument or theory
       [syn: outline, synopsis, abstract, precis]
    3: a schematic or preliminary plan [syn: outline, schema,
       scheme]
    v 1: describe roughly or briefly or give the main points or
         summary of; "sketch the outline of the book"; "outline his
         ideas" [syn: sketch, outline, adumbrate]
    2: draw up an outline or sketch for something; "draft a speech"
       [syn: draft, outline]
    3: trace the shape of [syn: delineate, limn, outline]

Moby Thesaurus II by Grady Ward, 1.0:

240 Moby Thesaurus words for "outline":
   abbreviation, abbreviature, abrege, abridge, abridgment, abstract,
   adumbrate, adumbration, alphabet, article, basics, block in,
   block out, blueprint, border, bound, boundaries, boundary, bounds,
   bourns, brief, bring to life, broad lines, brouillon, capsule,
   capsulize, cartoon, catalog, catalogue raisonne, causerie,
   chalk out, character, characterize, chart, circumference,
   circumscription, compass, compend, condensation, condense,
   condensed version, configuration, confines, conformation,
   conspectus, contour, coordinates, copy, cortex, covering, crust,
   define, delineate, delineation, depict, descant, describe, design,
   detail, diagram, digest, discourse, discussion, disquisition,
   dissertation, draft, draw, drawing, ebauche, echo, edge, edges,
   elements, elevation, enumerate, envelope, epidermis, epitome,
   esquisse, essay, etude, evoke, examination, excursus, exposition,
   express, exterior, external, facade, face, facet, feature,
   features, figuration, figure, first approach, first principles,
   first steps, footprint, form, framework, fringe, fringes, front,
   galbe, gestalt, give words to, grammar, graph, ground plan, head,
   hem, homily, hornbook, house plan, ichnography, induction,
   integument, introductory study, itemize, lay out, layout,
   limitations, limits, limn, line, lineaments, lineation, lines,
   lucubration, main features, marches, margin, memoir, metes,
   metes and bounds, monograph, morceau, note, number, nutshell,
   outer face, outer layer, outer side, outer skin, outlines, outside,
   outskirts, overview, paint, pale, pandect, paper, paragraph,
   parameters, parse, pattern, perimeter, periphery, picture, piece,
   plan, plot, portray, precis, preliminary study, primer, principia,
   principles, profile, projection, prolegomenon, recapitulation,
   reflection, reflex, relief, render, represent, research paper,
   resolve, resume, review, rim, rind, rough, rough in, rough out,
   rubric, rudiments, run-down, scan, scenario, schema, schematize,
   scheme, screed, set forth, shadow, shape, shapes, shell, shorten,
   shortened version, silhouette, skeleton, sketch, sketch out, skin,
   skirt, skirts, skyline, special article, study, summarize, summary,
   superficies, superstratum, surface, surround, survey, syllabus,
   synopsis, synopsize, table, table of contents, term paper, theme,
   thesis, thumbnail sketch, top, topical outline, tournure, trace,
   tract, tractate, treatise, treatment, verges, working drawing,
   write