/ Dictionary / Index N nephridium: Meaning and Definition of Find definitions for: ne•phrid•i•um Pronunciation: (nu-frid'ē-um), [key] — pl. -phrid•i•a the excretory organ of many invertebrates, consisting of a tubule with one end opening into the body cavity and the other opening into a pore at the body surface. Random House Unabridged Dictionary, Copyright © 1997, by Random House, Inc., on Infoplease. nephric nephrite Related Content Daily Word Quiz: clairvoyant Analogy of the Day: Today’s Analogy Spelling Bee: Today’s Spelling Bee Frequently Misspelled Words Frequently Mispronounced Words Easily Confused Words Writing & Language