/ Dictionary / Index C cummingtonite: Meaning and Definition of Find definitions for: cum•ming•ton•ite Pronunciation: (kum'ing-tu-nīt"), [key] — n. an amphibole mineral, magnesium-iron silicate, similar in composition to anthophyllite but richer in iron. Random House Unabridged Dictionary, Copyright © 1997, by Random House, Inc., on Infoplease. Cummings cumquat Related Content Daily Word Quiz: philately Analogy of the Day: Today’s Analogy Spelling Bee: Today’s Spelling Bee Frequently Misspelled Words Frequently Mispronounced Words Easily Confused Words Writing & Language