Source : Webster's Revised Unabridged Dictionary (1913)

Gown \Gown\, n. [OE. goune, prob. from W. gwn gown, loose robe,
   akin to Ir. gunn, Gael. g[`u]n; cf. OF. gone, prob. of the
   same origin.]
   1. A loose, flowing upper garment; especially:
      (a) The ordinary outer dress of a woman; as, a calico or
          silk gown.
      (b) The official robe of certain professional men and
          scholars, as university students and officers,
          barristers, judges, etc.; hence, the dress of peace;
          the dress of civil officers, in distinction from
          military.

                He Mars deposed, and arms to gowns made yield.
                                                  --Dryden.
      (c) A loose wrapper worn by gentlemen within doors; a
          dressing gown.

   2. Any sort of dress or garb.

            He comes . . . in the gown of humility. --Shak.

Source : WordNet®

gown
     n 1: long, usually formal, woman's dress
     2: protective garment worn by surgeons during operations [syn:
        {surgical gown}, {scrubs}]
     3: outerwear consisting of a long flowing garment used for
        official or ceremonial occasions [syn: {robe}]
     v : dress in a gown