Source : Webster's Revised Unabridged Dictionary (1913)

Halcyon \Hal"cy*on\, n. [L. halcyon, alcyon, Gr.?: F. halcyon.]
   (Zo["o]l.)
   A kingfisher. By modern ornithologists restricted to a genus
   including a limited number of species having omnivorous
   habits, as the sacred kingfisher ({Halcyon sancta}) of
   Australia.

         Amidst our arms as quiet you shall be As halcyons
         brooding on a winter sea.                --Dryden.

Halcyon \Hal"cy*on\, a.
   1. Pertaining to, or resembling, the halcyon, which was
      anciently said to lay her eggs in nests on or near the sea
      during the calm weather about the winter solstice.

   2. Hence: Calm; quiet; peaceful; undisturbed; happy. ``Deep,
      halcyon repose.'' --De Quincy.

Source : WordNet®

halcyon
     adj 1: idyllically calm and peaceful; suggesting happy
            tranquillity; "a halcyon atmosphere"
     2: marked by peace and prosperity; "a golden era"; "the halcyon
        days of the clipper trade" [syn: {golden}, {prosperous}]
     n 1: (Greek mythology) a woman who was turned into a kingfisher
          [syn: {Alcyone}]
     2: a large kingfisher widely distributed in warmer parts of the
        Old World [syn: {genus Halcyon}]
     3: a mythical bird said to breed at the time of the winter
        solstice in a nest floating on the sea and to have the
        power of calming the winds and waves