su·per·no·va (so?o?p?r-n??v?)n. pl. su·per·no·vae (-v?) or su·per·no·vas A rare celestial phenomenon involving the explosion of a star and resulting in an extremely bright, short-lived object that emits vast amounts of energy. Depending on the type of supernova, the explosion may completely destroy the star, or the stellar core may survive to become a neutron star.American Heritage® Dictionary of the English Language, Fifth Edition. Copyright © 2016 by Houghton Mifflin Harcourt Publishing Company. Published by Houghton Mifflin Harcourt Publishing Company. All rights reserved.supernova (?su?p??n??v?) n, pl -vae (-vi?) or -vas (Astronomy) a star that explodes catastrophically owing to either instabilities following the exhaustion of its nuclear fuel or gravitational collapse following the accretion of matter from an orbiting companion star, becoming for a few days up to one hundred million times brighter than the sun. The expanding shell of debris (the supernova remnant) creates a nebula that radiates radio waves, X-rays, and light, for hundreds or thousands of years. Compare novaCollins English Dictionary ? Complete and Unabridged, 12th Edition 2014 © HarperCollins Publishers 1991, 1994, 1998, 2000, 2003, 2006, 2007, 2009, 2011, 2014su?per?no?va (?su p?r?no? v?) n., pl. -vas, -vae (-vi) a nova millions of times brighter than the sun. [1925?30] Random House Kernerman Webster’s College Dictionary, © 2010 K Dictionaries Ltd. Copyright 2005, 1997, 1991 by Random House, Inc. All rights reserved.su·per·no·va (so?o?p?r-n??v?) Plural supernovae (so?o?p?r-n??v?) or supernovas A massive star that undergoes a sudden, extreme increase in brightness and releases an enormous burst of energy. This occurs as a result of the violent explosion of most of the material of the star, triggered by the collapse of its core. See more at star. Compare nova. See Note at pulsar.The American Heritage® Student Science Dictionary, Second Edition. Copyright © 2014 by Houghton Mifflin Harcourt Publishing Company. Published by Houghton Mifflin Harcourt Publishing Company. All rights reserved.supernovaA star that explodes and leaves a neutron star remnant.Dictionary of Unfamiliar Words by Diagram Group Copyright © 2008 by Diagram Visual Information Limited