/ Dictionary / Index N negative ion: Meaning and Definition of Find definitions for: neg'ative i'on Pronunciation: [key] — Physics, Chem. Physics,Chem. See under(def. 1). Random House Unabridged Dictionary, Copyright © 1997, by Random House, Inc., on Infoplease. negative income tax negative lens 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