Origin: Germanic Old English suffix
Kingdom has 7 different meanings across 1 category:
a country with a king as head of state
"The tour group visited several European kingdoms, including Sweden and Denmark, to see their royal palaces."
a monarchy with a king or queen as head of state
"The entire kingdom fell silent when news arrived that the young heir had been named the new monarch."
the highest taxonomic group into which organisms are grouped; one of five biological categories: Monera or Protoctista or Plantae or Fungi or Animalia
"During our biology class, we learned that humans belong to the kingdom Animalia."
a basic group of natural objects
"The biology textbook introduced students to the five main kingdoms, including plants and animals."
A realm having a king and/or queen as its actual or nominal sovereign.
"After years of civil war, the neighboring kingdom finally recognized his family's rightful claim to the throne."
In plain English: A kingdom is a country ruled by a king or queen.
"After years of searching for his lost cat, he finally found it in the backyard kingdom where all the other stray cats lived."
Usage: Use "kingdom" to refer to a sovereign state ruled by a monarch rather than a president or prime minister, such as the United Kingdom or the Kingdom of Saudi Arabia. It can also describe a vast natural region or a metaphorical sphere of influence, like being in someone's kingdom.
Kingdom comes from the Old English word for "king's realm," formed by combining king and the suffix -dom. The term entered Middle English with this same meaning, referring to the territory ruled by a monarch.