The Collaborative International Dictionary of English v.0.48:

Balcony \Bal"co*ny\ (b[a^]l"k[-o]*n[y^]; 277), n.; pl.
   Balconies (b[a^]l"k[-o]*n[i^]z). [It. balcone; cf. It.
   balco, palco, scaffold, fr. OHG. balcho, palcho, beam, G.
   balken. See Balk beam.]
   1. (Arch.) A platform projecting from the wall of a building,
      usually resting on brackets or consoles, and inclosed by a
      parapet; as, a balcony in front of a window. Also, a
      projecting gallery in places of amusement; as, the balcony
      in a theater.
      [1913 Webster]

   2. A projecting gallery once common at the stern of large
      ships.
      [1913 Webster]

   Note: "The accent has shifted from the second to the first
         syllable within these twenty years." --Smart (1836).
         [1913 Webster]

WordNet (r) 3.0 (2006):

balcony
    n 1: an upper floor projecting from the rear over the main floor
         in an auditorium
    2: a platform projecting from the wall of a building and
       surrounded by a balustrade or railing or parapet

Moby Thesaurus II by Grady Ward, 1.0:

42 Moby Thesaurus words for "balcony":
   auditorium, box, box seat, catafalque, dais, dress circle,
   emplacement, estrade, fauteuil, floor, gallery, heliport, hustings,
   landing, landing pad, landing stage, launching pad, loge,
   nigger heaven, orchestra, orchestra circle, paradise, parquet,
   parquet circle, parterre, peanut gallery, pit, platform, podium,
   proscenium boxes, pulpit, rostrum, soapbox, stage, stall,
   standing room, step terrace, stump, terrace, theatre stall,
   tribunal, tribune