1.Definition: 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"

Related Noun(s):kingdom, land

Category: General

2.Definition: a knowledge domain that you are interested in or are communicating about

"It was a limited realm of discourse", "Here we enter the region of opinion", "The realm of the occult"

Related Noun(s):region

Category: General

3.Definition: the domain ruled by a king or queen

Related Noun(s):kingdom

Category: Places