/ Dictionary / Index S superclass: Meaning and Definition of Find definitions for: su•per•class Pronunciation: (s'pur-klas", -kläs"), [key] — n. Biol. a category of related classes within a phylum or subphylum. a subphylum. Random House Unabridged Dictionary, Copyright © 1997, by Random House, Inc., on Infoplease. See also: superclass (Thesaurus) supercity supercluster 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