/ Dictionary / Index N neutron star: Meaning and Definition of Find definitions for: neu'tron star" Pronunciation: [key] — n. an extremely dense, compact star composed primarily of neutrons, esp. the collapsed core of a supernova. Random House Unabridged Dictionary, Copyright © 1997, by Random House, Inc., on Infoplease. neutron number neutrophil Related Content Daily Word Quiz: agitated Analogy of the Day: Today’s Analogy Spelling Bee: Today’s Spelling Bee Frequently Misspelled Words Frequently Mispronounced Words Easily Confused Words Writing & Language