The Collaborative International Dictionary of English v.0.48:

Synopsis \Syn*op"sis\, n.; pl. Synopses. [L., from Gr. ?; sy`n
   with, together + ? a sight, view, from the root seen in E.
   optic.]
   A general view, or a collection of heads or parts so arranged
   as to exhibit a general view of the whole; an abstract or
   summary of a discourse; a syllabus; a conspectus.
   [1913 Webster]

         That the reader may see in one view the exactness of
         the method, as well as force of the argument, I shall
         here draw up a short synopsis of this epistle. --Bp.
                                                  Warburton.
   [1913 Webster]

   Syn: Abridgment; compendium; epitome; abstract; summary;
        syllabus; conspectus. See Abridgment.
        [1913 Webster] Synoptic

WordNet (r) 3.0 (2006):

synopsis
    n 1: a sketchy summary of the main points of an argument or
         theory [syn: outline, synopsis, abstract, precis]

Moby Thesaurus II by Grady Ward, 1.0:

50 Moby Thesaurus words for "synopsis":
   abbreviation, abbreviature, abrege, abridgement, abridgment,
   abstract, apercu, apocope, breviary, brief, capsule, compend,
   compendium, compression, condensation, condensed version,
   conspectus, curtailment, digest, draft, elision, ellipsis, epitome,
   epitomization, foreshortening, head, outline, overview, pandect,
   precis, recap, recapitulation, reduction, resume, retrenchment,
   review, rubric, shortened version, shortening, skeleton, sketch,
   summary, summation, survey, syllabus, syncope, telescoping,
   thumbnail sketch, topical outline, truncation