realm (
http://definr.com/realm)
n 1: a domain in which something is dominant; "the untroubled
kingdom of reason"; "a land of make-believe"; "the rise
of the realm of cotton in the south" [syn:
kingdom,
land]
2: a knowledge domain that you are interested in or are
communicating about; "it was a limited domain of
discourse"; "here we enter the region of opinion"; "the
realm of the occult" [syn:
domain,
region]
3: the domain ruled by a king or queen [syn:
kingdom]