The Collaborative International Dictionary of English v.0.48:
Igloo \Ig"loo\, n. 1. An Eskimo snow house. [1913 Webster] 2. (Zool.) A cavity, or excavation, made in the snow by a seal, over its breathing hole in the ice. [1913 Webster]WordNet (r) 3.0 (2006):
igloo n 1: an Eskimo hut; usually built of blocks (of sod or snow) in the shape of a dome [syn: igloo, iglu]