noun
(archaic or law and rhetoric) A territory or state, as ruled by an absolute authority, especially by a king; a kingdom.
(also figurative) A sphere of knowledge or of influence; a domain.
(biology, ecology) A primary zoogeographical division of the earth's surface.
(virology, taxonomy) A taxonomic rank in the phylogeny of viruses, higher than kingdoms.
(archaic) A region or zone forming part of a cosmological system.