kingdom in WordNet English dictionary

1. a basic group of natural objects
   kingdom 
   
2. a monarchy with a king or queen as head of state
   kingdom 
   
3. the highest taxonomic group into which organisms are grouped; one of five biological categories: Monera or Protoctista or Plantae or Fungi or Animalia
   kingdom 
   
4. the domain ruled by a king or queen
   kingdom  realm 
   
5. a country with a king as head of state
   kingdom 
   
6. 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"
   kingdom  land  realm