/ Dictionary / Index N neutrino: Meaning and Definition of Find definitions for: neu•tri•no Pronunciation: (n-trē'nō, ny-), [key] — pl. -nos. any of the massless or nearly massless electrically neutral leptons. There is a distinct kind of neutrino associated with each of the massive leptons. Cf. Random House Unabridged Dictionary, Copyright © 1997, by Random House, Inc., on Infoplease. See also: neutrino (Thesaurus) neutral zone neutrino astronomy Related Content Daily Word Quiz: philtrum Analogy of the Day: Today’s Analogy Spelling Bee: Today’s Spelling Bee Frequently Misspelled Words Frequently Mispronounced Words Easily Confused Words Writing & Language