/ Dictionary / Index N natrium: Meaning and Definition of Find definitions for: na•tri•um Pronunciation: (nā'trē-um), [key] — n. (formerly) sodium. Random House Unabridged Dictionary, Copyright © 1997, by Random House, Inc., on Infoplease. NATO natriuresis Related Content Daily Word Quiz: eureka Analogy of the Day: Today’s Analogy Spelling Bee: Today’s Spelling Bee Frequently Misspelled Words Frequently Mispronounced Words Easily Confused Words Writing & Language