/ Dictionary / Index R roscoelite: Meaning and Definition of Find definitions for: ros•coe•lite Pronunciation: (ros'kō-līt"), [key] — n. Mineral. a brown variety of muscovite in which some aluminum is replaced by vanadium. Random House Unabridged Dictionary, Copyright © 1997, by Random House, Inc., on Infoplease. roscoe Roscommon Related Content Daily Word Quiz: gregarious Analogy of the Day: Today’s Analogy Spelling Bee: Today’s Spelling Bee Frequently Misspelled Words Frequently Mispronounced Words Easily Confused Words Writing & Language