Source : Webster's Revised Unabridged Dictionary (1913)

Igloo \Ig"loo\, n.
   1. An Eskimo snow house.

   2. (Zo["o]l.) A cavity, or excavation, made in the snow by a
      seal, over its breathing hole in the ice.

Source : WordNet®

igloo
     n : an Eskimo hut; usually built of blocks (of sod or snow) in
         the shape of a dome [syn: {iglu}]