/ Dictionary / Index C coffinite: Meaning and Definition of Find definitions for: cof•fin•ite Pronunciation: (kô'fi-nīt, kof'i-), [key] — n. a mineral, black uranous silicate, USiO, an important ore of uranium. Random House Unabridged Dictionary, Copyright © 1997, by Random House, Inc., on Infoplease. coffin corner coffin nail Related Content Daily Word Quiz: reclusive Analogy of the Day: Today’s Analogy Spelling Bee: Today’s Spelling Bee Frequently Misspelled Words Frequently Mispronounced Words Easily Confused Words Writing & Language