The Collaborative International Dictionary of English v.0.48:

Synoptic \Syn*op"tic\, Synoptical \Syn*op"tic*al\, a. [Gr. ?:
   cf. F. synoptique. See Synopsis.]
   Affording a general view of the whole, or of the principal
   parts of a thing; as, a synoptic table; a synoptical
   statement of an argument. "The synoptic Gospels." --Alford.
   -- Syn*op"tic*al*ly, adv.
   [1913 Webster]

The Collaborative International Dictionary of English v.0.48:

Synoptic \Syn*op"tic\, n.
   One of the first three Gospels of the New Testament. See
   Synoptist.
   [1913 Webster]

WordNet (r) 3.0 (2006):

synoptic
    adj 1: presenting a summary or general view of a whole; "a
           synoptic presentation of a physical theory"
    2: presenting or taking the same point of view; used especially
       with regard to the first three gospels of the New Testament;
       "synoptic sayings" [syn: synoptic, synoptical]

Moby Thesaurus II by Grady Ward, 1.0:

33 Moby Thesaurus words for "synoptic":
   across-the-board, all-comprehensive, all-inclusive, blanket, brief,
   compact, compendious, complete, comprehensive, concise, curt,
   curtal, curtate, decurtate, encyclopedic, global, instantaneous,
   little, low, omnibus, over-all, panoramic, short, short and sweet,
   succinct, summary, sweeping, total, transient, universal, whole,
   without exception, without omission