a state or government having a king or queen as its head.

anything conceived as constituting a realm or sphere of independent action or control

the kingdom of thought.

a realm or province of nature, esp. one of the three broad divisions of natural objects

the animal, vegetable, and mineral kingdoms.

Biology . a taxonomic category of the highest rank, grouping together all forms of life having certain fundamental characteristics in common

in the five-kingdom classification scheme adopted by many biologists, separate kingdoms are assigned to animals (Animalia), plants (Plantae), fungi (Fungi), protozoa and eucaryotic algae (Protista), and bacteria and blue-green algae (Monera).

the spiritual sovereignty of God or Christ.

the domain over which the spiritual sovereignty of God or Christ extends, whether in heaven or on earth.

noun

commonwealth , country , county , crown , division , domain , dominion , dynasty , empire , field , lands , monarchy , nation , possessions , principality , province , realm , reign , rule , scepter , sovereignty , sphere , state , suzerainty , sway , territory , throne , tract , demesne , dukedom , jurisdiction , vizierate