A taxonomic category of related organisms constituting a major division of a kingdom.(noun)
American Heritage(R) Dictionary of the English Language, Fifth Edition. Copyright (c) 2011 by Houghton Mifflin Harcourt Publishing Company. Published by Houghton Mifflin Harcourt Publishing Company. All rights reserved.
Use "subkingdom" in a sentence
"Given this remarkable floristic endemism, New Caledonia is often considered a distinct floristic subkingdom."
"Maybe either the king came round on circuit or there was some system of delegates (maybe the thane(s)?) to a bigger kingdom- or subkingdom-sized moot?"
"Regards Protozoa as subkingdom and the four great divisions as phyla."