1. A monarchy with a king or queen as head of state
   "The United Kingdom is a constitutional monarchy"
    
2. A country with a king as head of state
   "The Kingdom of Norway is a constitutional monarchy"
    
3. The domain ruled by a king or queen
   "The kingdom of Bhutan is nestled in the Himalayas";
   - realm
    
4. The highest taxonomic group into which organisms are grouped; one of five biological categories: Monera, Protoctista, Plantae, Fungi or Animalia
   "Fungi were once classified under the plant kingdom but are now recognized as a separate kingdom"
    
5. A basic group of natural objects
   "The animal kingdom includes a vast diversity of species"
    
6. A domain in which something is dominant
   "the untroubled kingdom of reason";
   - land, realm

Derived forms: kingdoms

Type of: area, arena, country, demesne, domain, field, group, grouping, land, monarchy, orbit, sphere, state, taxon, taxonomic category, taxonomic group

Encyclopedia: Kingdom, Sara