/ Dictionary / Index S supernova remnant: Meaning and Definition of Find definitions for: superno'va rem"nant Pronunciation: [key] — Astron. Astron. an expanding shell of gas, with accompanying strong radio and x-ray emissions, produced by a supernova. Random House Unabridged Dictionary, Copyright © 1997, by Random House, Inc., on Infoplease. supernova supernumerary 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