noun

1. Obsolete the position, rank, or power of a king
2. a government or country headed by a king or queen; monarchy
3. a realm; domain; sphere the kingdom of poetry
4. any of the three great divisions into which all natural objects have been classified (the animal, vegetable, and mineral kingdoms)
5. the spiritual realm of God
6. Biol. a major category in the classification of animals, plants, etc., ranking above a phylum or division: in some systems it ranks below a superkingdom: the Latinized kingdom names are capitalized but not italicized (Ex.: Monera, monerans)

Etymology: ME < OE cyningdom: see king & -dom