/ Dictionary / Index S subkingdom: Meaning and Definition of Find definitions for: sub•king•dom Pronunciation: (sub-king'dum, sub'king"-), [key] — n. Biol. a category of related phyla within a kingdom. Random House Unabridged Dictionary, Copyright © 1997, by Random House, Inc., on Infoplease. See also: subkingdom (Thesaurus) subjunctive sublanguage Related Content Daily Word Quiz: neologism Analogy of the Day: Today’s Analogy Spelling Bee: Today’s Spelling Bee Frequently Misspelled Words Frequently Mispronounced Words Easily Confused Words Writing & Language