kingdom

from The American Heritage® Dictionary of the English Language, 5th Edition.

• noun A political or territorial unit ruled by a sovereign.
• noun The eternal spiritual sovereignty of God or Christ.
• noun The realm of this sovereignty.
• noun A realm or sphere in which one thing is dominant.
• noun In the Linnean taxonomic system, the highest taxonomic category into which organisms are grouped, based on fundamental similarities and common ancestry. One widely used taxonomic system designates five or six such groups: animals, plants, fungi, protists, and prokaryotes (often divided into bacteria and archaea). Other systems divide organisms into domains (eukaryotes, bacteria, and archaea) that replace or rank above kingdoms.
• noun One of the three main divisions (animal, vegetable, and mineral) into which natural organisms and objects have traditionally been classified.

from The Century Dictionary.

• noun The power or authority of a king; regal dominion; supreme rule.
• noun The state of being a king; kinghood; kingship.
• noun The territory or country subject to a king; the dominion of a king or monarch (see king, 1); in general, a domain; country.
• noun Anything conceived as constituting a realm or sphere of independent action or control: as, the kingdom of thought.
• noun In the New Testament, with the definite article, usually in fuller phrase the kingdom of God, or the kingdom of heaven, the spiritual reign of God as supreme king, and over subjects loyally accepting it: generally conceived as founded by the Messiah, and therefore a Messianic kingdom.
• noun In natural history, one of the three great divisions in which natural objects are ranked in classification—namely, the animal, vegetable, and mineral kingdoms

from the GNU version of the Collaborative International Dictionary of English.

• noun The rank, quality, state, or attributes of a king; royal authority; sovereign power; rule; dominion; monarchy.
• noun The territory or country subject to a king or queen; the dominion of a monarch; the sphere in which one is king or has control.
• noun An extensive scientific division distinguished by leading or ruling characteristics; a principal division; a department. In modern biology, the division of life into five kingdoms is widely used for classification.
• noun See under Animal.
• noun The authority or dominion of God.
• noun See under Mineral.
• noun See under United.
• noun See under Vegetable.

from Wiktionary, Creative Commons Attribution/Share-Alike License.

• noun A nation having as supreme ruler a king and/or queen.
• noun biology, taxonomy A rank in the classification of organisms, below domain and above phylum; a taxon at that rank (e.g. the plant kingdom, the animal kingdom)

from WordNet 3.0 Copyright 2006 by Princeton University. All rights reserved.

• noun a monarchy with a king or queen as head of state
• noun a domain in which something is dominant
• noun the highest taxonomic group into which organisms are grouped; one of five biological categories: Monera or Protoctista or Plantae or Fungi or Animalia
• noun the domain ruled by a king or queen
• noun a basic group of natural objects
• noun a country with a king as head of state