The Collaborative International Dictionary of English v.0.48:

Western \West"ern\, a.
   [1913 Webster]
   1. Of or pertaining to the west; situated in the west, or in
      the region nearly in the direction of west; being in that
      quarter where the sun sets; as, the western shore of
      France; the western ocean.
      [1913 Webster]

            Far o'er the glowing western main.    --Keble.
      [1913 Webster]

   2. Moving toward the west; as, a ship makes a western course;
      coming from the west; as, a western breeze.
      [1913 Webster]

   Western Church. See Latin Church, under Latin.

   Western empire (Hist.), the western portion of the Roman
      empire, as divided, by the will of Theodosius the Great,
      between his sons Honorius and Arcadius, a. d. 395.
      [1913 Webster]

WordNet (r) 3.0 (2006):

western
    adj 1: relating to or characteristic of the western parts of the
           world or the West as opposed to the eastern or oriental
           parts; "the Western world"; "Western thought"; "Western
           thought" [ant: eastern]
    2: of or characteristic of regions of the United States west of
       the Mississippi River; "a Western ranch" [ant: eastern]
    3: lying toward or situated in the west; "our company's western
       office"
    4: of wind; from the west [syn: westerly, western]
    n 1: a film about life in the western United States during the
         period of exploration and development [syn: Western,
         horse opera]
    2: a sandwich made from a western omelet [syn: western,
       western sandwich]